Review at the end of the first year of science.

1. Structure that plays a supporting and protecting role in plant cell structure ()

A. cell membrane; B. cytoplasm; C. cell wall; D. nucleus.

2. To move the image in the upper right corner of the visual field to the center of the visual field, the direction of moving the slide is ().

A. upper right corner; B. lower right corner; C. upper left corner; D. lower left corner.

3. In the discus competition of the sports meeting, if the referee pulls the tape measure too tightly, the measured value will be ().

A.it's too big; B. too small; C. unchanged; D. it's all possible.

4. When weighing the quality of eggs with the adjusted balance, if the pointer is to the right, the following operation is correct ().

A. add weight to the plate; B. reducing the weight in the board;

C, moving the roaming code to the right; Adjust the balance nut to the left.

5. Observe with a microscope. When the light is too strong, you should choose ().

A. large aperture, flat mirror; B. Large aperture, concave mirror;

C. small aperture, flat mirror; D. Small aperture, concave mirror.

6. The significant difference between fungi and green plants in structure is ()

A. no vacuoles; B. no cell wall;

C. no chloroplasts; An unformed nucleus.

7. About thermometers and mercury thermometers, the following statement is true ()

A. the temperature of boiling water can be measured;

B, the measured object can be left for reading;

C. there is a particularly thin bend in the inner diameter;

D. they are all made by using the characteristics of liquid expanding when heated and contracting when cooled.

8. The human body from small to large structure level is ()

A, cells, tissues, organs, systems, human body;

B. Cells, organs, tissues, systems and human bodies;

C. Cells, organs, systems, tissues and human bodies;

D. cells, systems, tissues, organs and human bodies.

9. Chromosomes appear in cells, and the changes of cell morphology and function belong to () respectively.

A. cell growth and cell division; B. cell division and cell differentiation;

C. cell differentiation and cell growth; Cell differentiation and cell division.

10. What kind of microorganism is added to milk to make yogurt ()

A. Escherichia coli; B. lactobacillus;

C. Bacillus subtilis; yeast

1 1. When observing oral epithelial cells with a microscope, it was found that there was no light spot in the field of vision, and the possible reason was ().

A. no slides are placed;

B, when making the film, no dye is used;

C. the objective lens is not aligned with the light hole;

D. epithelial cells are not scraped out of the mouth.

12. Among the following four structures, the one that belongs to the organ level is ().

A. blood; B. subcutaneous tissue; C. tendon; Blood vessels.

13. The thermometer measured Xiao Ming's temperature at 37.3 degrees Celsius. If the mercury column is not thrown back into the glass bulb, it will be used to measure the temperature of Xiao Gang and Wang Ping. If the actual body temperatures of Xiao Gang and Wang Ping are 37.65438 0℃ and 37.8℃ respectively, the results of the two measurements should be ().

A.37. 1℃ and 37.8℃; B 37.3℃ and 37.8℃;

C.37. 1℃ and 37.3℃; D. 37.3℃ and 37.3℃.

14. Measure a student's pulse with a watch and jump 75 times per minute, and the time required for each jump is ().

A.0.8 seconds; B.0.08 seconds; C. 0.6 seconds; D. 1.35 seconds.

15. The main organ for human digestion and absorption of food is ()

A. oral cavity; B. esophagus; C. stomach; D. small intestine.

16. The units used in biological classification are arranged from low to high ().

A. phylum, family, genus and species; B. families, genera and species of cladocera;

C. phylum of species, genera and subjects; Families, species, orders, phylum and genus.

17. The following plants without roots, stems and leaves are ().

A. ferns; Pumpkin; C. laver; D. cactus

18. Organisms will not become extinct because of individual death, because organisms have ().

A. growth characteristics; B. genetic characteristics;

C. reproductive characteristics; D. adaptive characteristics.

19. Chinese alligator belongs to ()

A. mammals; B. reptiles; C. amphibians; D. birds

20. There is a plant called Pteris vittata, which has pinnately compound leaves, underground stems, adventitious roots and sporangia on the back of leaves. So I guess it may belong to ()

A. ferns; Bryophytes;

C. gymnosperms; D. angiosperms

2 1. Some students accidentally cut their skin and bled when using a knife. This knife hurt his skin.

A. epidermis; B. genuine leather; C. subcutaneous tissue; D. fat layer.

22. A fish that lives in seaweed, when it is hurt by the enemy, its body immediately stands on its head like a plant, thus effectively avoiding the enemy's injury. This phenomenon is called ().

A. protective color; B. warning color; C. mimicry; D. adapt.

23. It was found that the south is high latitude, the north is middle latitude, the west is the western hemisphere, and the east is the eastern hemisphere. This person may be located in ()

A.20 W，60s； B. 160 E，60N；

C.20 W，60n； East longitude 160, south latitude 60.

2. Fill in the blanks:

1. When measuring the volume of liquid with a graduated cylinder, the graduated cylinder should be set at _ _ _ _ _ _, and the line of sight should be level with _ _ _ _ _ _ _ _.

2. The scale is a tool for measuring _ _ _ _ _ _, the balance is a tool for measuring, and the stopwatch is a tool for measuring _ _ _ _ _.

3. The normal body temperature is _ _ _ _ _ _, and the mass of one liter of water is about _ _ _, 8×106 nm = _ _ _ cm.

4. Before measuring the mass of an object with a balance, if the pointer points to

On the right side of the center line of the dial, it represents the _ _ _ _ end of the light beam.

When sinking, in order to balance the balance, the screw at the right end of the beam should be adjusted.

Mother moved to _ _ _ _ side. Weighing after leveling,

Put the object to be measured on the left tray, and the weight and stray code position on the right tray.

As shown in the figure, when the beam is balanced again, the mass of the measured object is _ _ _ _ _.

Xiaoming bought a bag of strawberries from the market. When he got home, he found some red juice at the bottom of the bag. The juice is _ _ _ _ _ _, mainly from _ _ _ in the cell structure.

6. All organisms with nuclei are _ _ _ _ _, including animals, plants and _ _ _ _ _.

7. According to international regulations, the earth is divided into the eastern hemisphere and the western hemisphere by _ _ _ _ _ _ _ _ _ _ _ _. The latitude of the equator is _ _ _ _ _ _, and the latitude of the North Pole is _ _ _ _.

8. The three elements of a map are _ _ _ _ _ _ _ _ _ _ _ _.

9. The calibration data of thermometer is inaccurate. The thermometer is placed in the mixture of ice and water, reading 2℃, and placed in boiling water at standard atmospheric pressure, reading 102℃. If placed indoors, the measured temperature is 20℃, then the actual indoor temperature is _ _ _ _ _.

10. In biological taxonomic units, the most common feature of plants is _ _ _ _ _.

1 1. Plants can be divided into two categories according to whether they can produce _ _ _ _ _. Among them, plants with seeds can be divided into _ _ _ _ _ _ _ plants and _ _ _ _ _ _ _ plants according to the seedless bags.

12. Among the following instruments, _ _ _ _ _ is used for heating, _ _ _ _ is used for taking a small amount of solid drugs, _ _ _ _ _ _ (fill in the serial number) ① beaker, ② dropper, ③ glass rod, ④ alcohol lamp, ⑤ medicine spoon and ⑤ test tube are commonly used for stirring.

13. The picture on the right shows the structure of human oral epithelial cells. Please answer:

Write the name of the structure shown in the figure:

A _ _ _ _ _, B _ _ _ _ _, C _ _ _ _ _.

(2) Compared with onion epidermal cells, human oral epithelial cells have no structure capable of photosynthesis, which is _ _ _ _ _.

3. Experimental design and inquiry:

1. Rapeseed with a diameter of only about 1mm cannot be weighed on the balance. Xiaogang wants to know the quality of 1 rapeseed. Please help him design a plan and weigh the quality of 1 rapeseed.

2. Please analyze after reading the article:

Willow leaves curl, flowers droop and the lake is boiling hot. Don't cook small fish! Ah, relax, relax! Dragonfly came, flying very low, hovering on the lake, reporting good news, "It's going to rain, it's going to rain!" " "

(1) What are the creatures mentioned in the essay: _ _ _ _ _ _ _ _ _;

(2) Can you tell us why they are living things?

(3) What two categories can you divide them into? What is your classification basis?

References:

Use it if it works!

Science review materials for grade one in junior high school

chapter one

Measurement content instrument unit conversion relationship

Length scale (meter scale) m (m) 1 km = 1000 m

1 m = 100 cm = 1000 mm

1 m = 106 μ m = 109 nm.

Volume scale (meter scale),

Measuring cylinder and measuring cup m31m3 = 1000 liter.

1L = 1000ml

1 ml = 1 cm3

Mass balance (pallet balance) kilogram (kg) 1kg = 1000g.

Clock, watch (mechanical stop) seconds 1 hour =60 minutes =3600 seconds.

Temperature of thermometer in Celsius (℃)

1. Experiment is the most important link in scientific research.

2. In the experiment, we should gradually learn to use all kinds of instruments correctly and observe all kinds of experimental phenomena carefully.

Correctly record the experimental phenomena and measurement data, analyze and draw conclusions.

There are limitations in judging things only by human senses. 4. The size is P 10 page.

The unit of length is meter, the common unit of solid volume is cubic meter, and the common unit of liquid volume is liter and milliliter.

6. The commonly used length measuring tool is the scale. 7. How to use the scale correctly? (heavy, p. P 1 1)

8. A measuring cylinder or cup is used in the laboratory to measure the volume of liquid. When reading, the line of sight should be flush with the lowest point in the center of concave liquid level.

9. How to measure irregular objects? (page P 13, drainage method)

10. Before using the ruler, find its A zero scale line, B measuring range (maximum scale and measuring range) and C minimum scale.

1 1. The degree of heat and cold of an object is called temperature. 12. the principle of making ordinary liquid thermometer is that liquid expands when it heats up and contracts when it cools down.

13. What is the temperature structure? (glass bulb, glass tube, scale) 14. What are the usage methods and precautions of the thermometer?

15. The temperature of ice-water mixture is 0℃, and the temperature of boiling water is 100℃.

16. The thermometer model you know is P 16.

17. Mass is used to indicate how many substances an object contains. 18. The quality of an object is determined by the object itself and does not change with the changes of temperature, position, shape and state.

19. The instrument for measuring quality in the laboratory is a pallet balance. What is its structure? P 19 page

20. How to use the pallet scale correctly? (weight, P 19) 2 1. What should I pay attention to when using the tray? P 19 page

22. Understand the concepts of time and time interval. P20 Page 23. Master the reading method of mechanical stopwatch. (understand)

24. The process of scientific inquiry: finding and asking questions-establishing conjectures and hypotheses-making inquiry plans-obtaining facts and evidence-testing and evaluating-exchanging and discussing.

chapter two

1. The difference between living things and nonliving things: whether there is stress, whether it can grow, whether it needs nutrition, whether it can reproduce, whether it can breathe, whether it can exchange substances, etc.

2. The main difference between plants and animals: (different ways to obtain nutrition) Animals-direct intake of food; Plants-use sunlight, carbon dioxide and water for photosynthesis to make nutrients.

3. Classification of (animals) must be based on certain characteristics; Because the basis of classification is different, the classification results are also different.

Animals such as fish, birds and humans have a spine on their backs, which consists of many vertebrae, so they are called vertebrates.

5. Vertebrates are divided into fish, amphibians, reptiles, birds and mammals from low to high.

6. What are the similarities and differences between fish? P37 page

7. What happened to a frog's life: fertilized egg, tadpole, young frog, adult frog.

8. What are the similarities and differences between amphibians? They breathe with their lungs and skin.

9. What are the similarities and differences between reptiles? (P39) What are the similarities and differences between birds? (40 pages)

10, birds and mammals are characterized by constant body temperature, while mammals are characterized by whole body fur, viviparous and lactation.

1 1. Names, classification standards and results of five kinds of vertebrates. (page 43)

12, the representative animal names, classification standards and results of various invertebrates. (44 pages)

13. There is no skeleton in insects, but the exoskeleton has a protective effect in vitro. The body is divided into three parts: head, chest and abdomen, with three pairs of feet and two pairs of wings.

14, the difference between seed plants and seedless plants: whether there are seeds; The difference between angiosperms and gymnosperms: Does the seed have a pericarp?

15. Angiosperms are the most diverse and widely distributed plants, while mammals are the most widely distributed and functional animals.

16. What are the characteristics of ferns? What organs does it have? (49 pages)

What are the characteristics of bryophytes? What organs does it have?

What are the characteristics of algae? What organs does it have?

17, the representative plant names of three types of seedless plants. (49 pages)

18, plant classification standards and classification results. Classification standards and classification results of all living things. (page 50)

19, Robert Hook discovers cells. What he found was actually a cell wall, usually one to several tens of microns in size.

20. Structural cell membrane, nucleus and cytoplasm of animal cells. What are their main functions? Structure of plant cells: cell membrane, nucleus, cytoplasm, cell wall, vacuole and chloroplast. What are their main functions? (page 56)

Can express and judge the difference between animal and plant cells. Key points)

2 1, Schleiden and Wang Shi put forward the cell theory, and its main contents are as follows: (P57)

22. When a cell divides, a chromosome will appear in the nucleus of the mother cell, which will eventually be evenly distributed among the two daughter cells.

23. What is the significance of cell division? What is cell differentiation? (P59, recorded)

The characteristics of single-celled organisms: the individual is small, and all life is completed in one cell.

25. Chlamydomonas is a unicellular plant and paramecium is a unicellular animal. What are the names of their structures? Page P60, 6 1

26. A large number of bacteria multiply together to form bacterial colonies called colonies;

27. The volume of bacteria is smaller than that of ordinary cells (many); It depends on ready-made organic matter to survive; It has no chloroplast, no feeding structure and is called prokaryote because it has no nucleus.

28. What is the structure of bacteria? (P62) According to the morphology of bacteria, it can be divided into cocci, bacilli and spirillus.

29. Animals, plants and fungi belong to eukaryotes because they all have nuclei in their cells.

30. Fungi include molds, yeasts and edible fungi. , edible fungi have P64 pages.

3 1, food preservation methods include dry storage method, cold storage method, vacuum preservation method and heating method.

32. The concept of organization? (On page P66, pay attention to the difference between cell groups and colonies)

33. Tactile corpuscles with sense of touch, cold sensitive corpuscles that respond to cold feeling, thermosensitive corpuscles that respond to hot feeling, and nerve endings that respond to skin pain.

34. A structure composed of many tissues and having certain functions is called an organ.

35. The vegetative organs of angiosperms are roots, stems and leaves, and the reproductive organs are flowers and fruit seeds.

36. Digestive organs are divided into two categories, namely digestive tube and digestive gland (what are they? P7 1 page)

37. Tell how the digestive organs work in the process of food digestion and absorption. (page 72)

38. What are the eight systems of the human body called? (page 73)

39. The structural level of plants: cell-tissue-organ-plant.

The structural level of animals: cell-tissue-organ-system-animal body.

The structural level of human body: cell-tissue-organ-system-human body.

40, biological adaptability and diversity.

4 1, why is it that the existence of any kind of creature is meaningful? (Page 77, paras. 2 and 3)

42, the basic organization of plants (heavy)

Distribution of functional characteristics of organization names

Protect tissue, protect transparent, chloroplast-free, tightly arranged (flat) epidermal cells.

Vegetative tissues produce and store nutrients, including chloroplast mesophyll cells.

Mechanical organization support and protection

Meristem divides to produce new tips of cell roots, stems, etc.

Organic vein transport roots composed of water, inorganic salts and leaves absorbed by tissue transport substances.

43, the four basic tissues of the human body (heavy)

Distribution of functional characteristics of organization names

Epithelial tissue plays an important role in protection. Secondly, epithelial cells with dense absorption and secretion constitute the inner surfaces of skin, visceral surfaces and various lumen walls in the body.

Connective tissue transport, supporting cell gap is large, interstitial cells are many and widely distributed, and there are many blood, cartilage, tendons and so on.

Muscle tissue contracts and relaxes, producing motor muscle cells (heart muscle, skeletal muscle, smooth muscle), limbs and trunk, heart, stomach and intestine.

Nerve tissue receives stimulation, producing and conducting excited nerve cells, brain, spinal cord and nerves.

44, the structure of the microscope and its use. (heavy)

chapter three

1, "The Movement of Pencil on Basketball and Wood Block" How did the position of the pencil head change in basketball and wood block respectively? What is the difference? (similar to a ship sailing in the ocean)

2. The earth is a sphere with slightly flat poles and slightly bulging equator. The equatorial radius is 6378 km and the polar radius is 6357 km.

(the difference is 2 1 km), and the difference is only 0.33%. So it looks like a circle. The circumference of the equator is about 40 thousand kilometers.

3. Definition of meridian, latitude and equator (page 84); The position relationship between warp and weft is perpendicular to each other; The distance between equator and north and south poles is equal;

4. Shape: the warp is semi-circular and the weft is circular; Any object can use the latitude and longitude net to determine its position.

The Tropic of Cancer (south and north latitude) is 23.5 degrees, and the polar circle (south and north latitude) is 66.5 degrees; The dividing line between middle, low and high latitudes. (P86)

5. Narrative significance: ① 0 meridian; ② 0 parallel; ③ Meridian of ③20° W,160 E (synchronous exercise on page 36)

6. Map definition; Map type; (P86, page 87) Three elements of a map (scale, direction and legend);

7. Distinguish what is a large-scale map and what is a small-scale map (P89 page) (the large-scale map has a smaller field area and more detailed content); What is the meaning of each scale? (on the map, 1 cm represents the field distance? ) Three representations of directions on a map. (longitude and latitude network orientation method, pointing calibration orientation method, general orientation method)

8. The sun is a gas planet; The diameter of the sun is about10.40 billion kilometers, which is about 1 10 times that of the earth, and the average distance between the sun and the earth is about10.50 billion kilometers. The center temperature is150000℃, and the surface temperature is about 6000℃.

9. The average distance between the moon and the earth is about 384,400 kilometers, and the distance between the sun and the earth is 400 times. The moon is about 3476 kilometers in diameter, which is 1/400 of the diameter of the sun. The volume of the moon is 1/49 of the earth, and the mass of the moon is 1/8 1 of the earth.

10. There are three layers on the surface of the sun: photosphere, chromosphere and corona. Common solar activities are

Sunspots (photosphere), flares (chromosphere), prominence (chromosphere),

Solar wind (corona layer). Fill in the grades in brackets.

1 1, the sign of solar activity: the sum of sunspot numbers; The strongest manifestation of solar activity: flare

12, sunspot activity cycle: about 1 1 year; Calculation method of period. (Exercise book page 45, question 8)

13, the influence of solar activity on the earth: solar wind-affecting short-wave communication; Sunspots and flares-ultraviolet enhancement; Disturbing the magnetic field makes the compass unable to guide; Endangering interstellar navigation; Aurora appears at the poles; The flood disaster is related to this.

14, the use of astronomical telescopes.

15, the reason why the moon looks almost as big as the sun: the distance from the sun to the earth is much farther than that from the moon to the earth; The bright parts of the moon surface are mountains and plateaus, and the dark parts are plains and lowlands. The cause of the crater: meteorite impact.

16, the surface of the moon is covered with craters without air, water and life;

17, textbook figure 3-2 1: On the surface of the moon: ① How do mass and weight change respectively? What is the reason? ② What is the reason for the large temperature difference between day and night? ③ What is the reason why you can't hear the sound? (4) What other results did it lead to? Meteorite impact (P96)

18, the definition of constellation: (P98);

The ancient Greeks divided the sky into 48 constellations, the ancient China divided the sky into 28 nights, and now the world divides the sky.

Divided into 88 regions, that is, 88 constellations.

19, Polaris in Ursa minor, Vega in Lyra, Altair in Eagle, Sirius in Canis major,

The Big Dipper is in Ursa Major.

20 ways to find Polaris in the starry sky: (P 100 page)

2 1, Beidou bucket handle faces east in spring, Beidou bucket handle faces west in autumn, Beidou bucket handle faces south in summer and Beidou bucket handle faces north in winter (filling season).

Simple mastery: southeast, northwest, spring, summer, autumn and winter.

22, star map definition (P 100 page); The reason why the star map should be raised above the head and viewed from north to south is because the east-west direction on the star map is opposite to the east-west direction on the surface;

23, the definition of the moon phase, the various forms of the moon;

The principle of the formation of the moon phase: ① The moon itself is not luminous and opaque.

(2) The moon revolves around the earth, so that the relative positions of the sun, the earth and the moon change regularly within one month;

The law of moon phase formation: (new moon)-(waning moon)-(first quarter moon)-(convex moon)-(full moon).

-(convex moon)-(lower quarter moon)-(waning moon)-(new moon)

24. The shape of the moon phase is mainly the graphics of the first quarter moon and the second quarter moon (heavy but difficult).

The reason why the back of the moon can't be seen on the earth: The rotation period of the moon is basically the same as that of period of revolution.

26. The cycle of the first lunar month is 29.53 days: the new moon is the first day of the first lunar month, and the fifteenth or sixteenth lunar month.

27, Spring Festival, Lantern Festival, Dragon Boat Festival, Mid-Autumn Festival, Double Ninth Festival, the date of the lunar calendar and the moon phase are night. (Exercise Book Part 5 Question 4)

28. The phenomenon that the surface of the sun is completely or partially covered is called a solar eclipse; Its formation principle is: (P 107)

29, (P 107) is called an eclipse; Its formation principle is: because the earth blocks the sunlight, a long shadow area is formed on the backlight side of the earth. When the moon moves to the side of the earth facing away from the sun, the moon is blocked by the shadow of the earth, and an eclipse occurs.

30. When an eclipse occurs, where should the sun, the earth and the moon be? (day-month-place)

If there is an eclipse, where should the sun, earth and moon be? (Day-Earth-Month)

3 1, the solar eclipse may occur on the first day of the lunar calendar (the lunar phase is a new moon), and the lunar eclipse may occur on the fifteenth or sixteenth day of the lunar calendar (the lunar phase is a full moon); Why doesn't an eclipse happen every month? (Page P 108)

32. The process of solar eclipse is: starting from the western edge of sun gear and ending at the eastern edge; The process of lunar eclipse is that the surface of the moon first loses to the eastern edge and then returns to the western edge.

33. What's the difference between a solar eclipse and a lunar eclipse on the earth? Why? (It can be observed that the range of lunar eclipse is large (nearly half of the earth), because there is an eclipse when the moon enters the umbra of the earth, and the shadow area of the earth is relatively large; The observable range of solar eclipse is small, because only the moon can be observed in the long and narrow shadow area on the earth's surface. )

34. Question 4 on page 52 of the workbook: Understanding.

35. The members of the solar system are: the sun, nine planets, asteroids and comets. The names and order of the nine planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.

36. Comets are formed by freezing rock fragments, solid particles and water;

The most famous comet is Halley's Comet, whose period is 76 years. The next time is to return to Earth in 2062.

37. What is the meteor phenomenon? Meteor? (P 1 15) Meteorites include meteorites and meteorites.

38. The Milky Way is made up of many stars and interstellar matter. Its shape is: spiral structure, thick in the middle and thin around; The farthest celestial body observed by human beings is about 65.438+0.5 billion light years away from the Earth.

39. The structural level of the universe: Earth-Earth-Moon system-solar system-galaxy-galaxy-universe.

chapter four

1, an object with a certain melting temperature is called crystal, and an object without a certain melting temperature is called amorphous. The main differences between crystalline and amorphous are: whether there is a melting point; Whether it is crystal or amorphous, it absorbs heat when it melts.

2. The temperature at which the crystal melts is called the melting point A .. This is the characteristic of the crystal.

3. The temperature at which the temperature of the crystal remains constant during solidification is called B freezing point. The melting point A and the freezing point B of the same crystal are the same.

4. The melting point of naphthalene is 80℃, and that of sodium thiosulfate is 48℃. The melting point of water is 0℃

5. In the process of heating and melting, the temperature gradually rises before melting, and it is solid; When melting, the temperature is constant and the state is solid-liquid existence; After melting, the temperature gradually rises and becomes liquid. Note: Melting time is not heating time.

6. Evaporation is the vaporization phenomenon at any temperature; Boiling is a vaporization phenomenon at a certain temperature. Evaporation is carried out on the surface of liquid, and boiling is carried out on the surface and inside of liquid. (Fill in position)

7. The three influencing factors of evaporation are: (p 126),,.

8. When evaporating, the temperature of the liquid decreases and the temperature of the surrounding environment decreases. When the thermometer is taken out of alcohol, the reading will first drop and then rise. (The drop is because the alcohol on the glass bulb absorbs heat when it evaporates, and then it rises because the alcohol evaporates and returns to room temperature. )

9, boiling characteristics: at a certain temperature (boiling point), below this temperature, the liquid absorbs heat, the temperature rises, and does not boil; At this temperature, the liquid absorbs heat, the temperature is constant and it boils.

10. Liquefaction methods include: cooling and pressurizing (compressed gas volume).

1 1. Molecules are particles that make up matter; There are gaps between molecules; Molecules are constantly moving.

12, compare the molecular gap size and diffusion speed of solid, liquid and gas (except water). (Page 139, Page 140)

13, what is diffusion? (Page P 140)

14, the diffusion phenomenon can be explained: first, there are gaps between molecules, and second, molecules are constantly moving;

15, the speed of molecular movement is related to temperature. The higher the temperature of an object, the more intense the molecular movement.

16, ① Under certain conditions, the amount of soluble substances is limited;

② Under the same conditions, the solubility of different substances is different;

③ The solubility of a substance will change with the change of external conditions (such as temperature).

④ Some substances may be insoluble in water, but may be soluble in other substances;

⑤ Gas can also be dissolved in water, but the higher the liquid temperature, the weaker the solubility of gas.

17, sodium hydroxide releases heat when dissolved, and ammonium nitrate absorbs heat when dissolved.

When dissolved, the temperature of some substances will rise and heat will be released; After some substances are dissolved, the temperature will decrease, so they need to absorb heat.

Acidity and alkalinity are two properties of matter. Substances with properties are called acidic substances, and substances with alkalinity are called alkaline substances. Strong acids are as corrosive as strong bases.

19, common (including) acidic substances: sulfuric acid, hydrochloric acid, nitric acid, vinegar, (various fruits);

Common (containing) alkaline substances: caustic soda (sodium hydroxide), hydrated lime (calcium hydroxide), potassium hydroxide, barium hydroxide, ammonia water, baking soda, soda ash and various detergents.

20, the corrosive properties of concentrated sulfuric acid make white paper black; Some alkalis have certain decontamination ability and can be used as detergents.

2 1, acidic solution can turn purple litmus test solution red; Alkaline solution can turn purple litmus test solution blue.

22. How to use the pH test paper? PH value is an index reflecting the strength of acid and alkali of a substance, and its range is usually 0-14; The lower the PH value, the stronger the acidity; The higher the PH value, the stronger the alkalinity, and the substance with PH value equal to 7 is neutral.

23. The main difference between physical change and chemical change is whether new substances are produced.

24. Only in chemical changes can we show the nature of chemical properties, and we can also show the nature of physical properties without chemical changes.

25. Physical attributes include: page P 155.

Belong to the chemical nature are:

26. Pay attention to experience and understand the difference between change and nature and the expression of nature.

27, material state and heat change diagram (key)