Scientific knowledge points in the second volume of the sixth grade

1, (magnifying glass) is one of the commonly used observation bases. A magnifying glass is a transparent (convex lens) with a thick center and a thin edge. Magnifier has the function of (magnifying the image of the object), and you can see more (details) by observing the object with a magnifying glass.

2. (Magnifier) can enlarge the image of an object and show the details that people can't see clearly with the naked eye, so that we can get more information. And widely used in many aspects of people's life and production.

3. The magnification of a magnifying glass has nothing to do with (the diameter of the lens), but with (the convexity of the lens). Magnifying glass (the greater the convexity, the greater the magnification).

4, the correct use of magnifying glass is:

(1) Move the magnifying glass: the observed object does not move, and the distance between human eyes and the observed object remains unchanged. The hand-held magnifying glass directly moves back and forth between the human eye and the observed object until the figure is large and clear;

(2) Move the observed object: move the magnifying glass in front of your eyes and move the observed object until the figure becomes bigger and clearer.

The earliest convex lens used by human beings is made of (transparent crystal). /kloc-In the 3rd century, an English bishop, Grotester, first proposed the application of magnifying devices, and his students (Bacon) designed and manufactured glasses that could improve their eyesight according to his suggestions.

6. Many details that can't be observed with naked eyes can be observed with observation tools. For example, through a magnifying glass, you can see the (compound eyes) of flies, the "ears" of crickets are on the inside of feet, and the wings of butterflies are covered with small colored scales (flat fine hairs).

7. Insects have a keen sense of smell. It is said that because of their (tentacles), tentacles are their ("nose").

8. Two (convex lenses) together can enlarge the image of an object, which is the early (microscope). The invention of (microscope) is a great leap for human beings to know the world, which makes human beings enter a (microscopic world).

9. Particles of salt, sugar, alkaline noodles and monosodium glutamate are all solids with regular geometric shapes. People call this solid substance (crystal).

10, many rocks are made of (mineral crystals). For example, granite is composed of mineral crystals such as feldspar, mica and quartz.

1 1. Most solid substances in nature are (crystals) or consist of (crystals). Crystal shapes (various), but they are all regular. Some crystals are larger and visible to the naked eye, while others are smaller and can only be seen under a magnifying glass or microscope.

12, a biologist (Levin Hooke) made the world's earliest metal structure (microscope) which can be magnified nearly 300 times, and discovered (microorganism). In order to see smaller objects, people developed (electron microscope) and (scanning tunneling microscope). An electron microscope can magnify an object 2 million times.

13, a British scientist (robert hooke) saw (cells) for the first time in the world with a self-made compound microscope.

14, the microscope is mainly composed of (eyepiece) (adjusting knob) (objective lens) (stage) (mirror) and so on. The use steps of the microscope are: (placing)-(aiming at light)-(loading)-(focusing)-(observing).

15. Experiments prove that onion epidermis is composed of (cells), and a large number of research facts show that life is composed of (cells).

16, (cell) is the most basic (structural unit) and the most basic (functional unit) of living things. The establishment of (cell theory) is considered as one of the three major discoveries of natural science in the19th century.

17. Through observation, we know that the TV screen is actually composed of many (fluorescent spots), and the color of the color screen is composed of three colors: (red), (blue) and (green).

18. Aphids like to suck (juice) from twigs. Aphids are as big as (the eye of a needle). We can see their limbs clearly under the magnifying glass of (10). The natural enemy of aphids is (Chrysopa).

19, observation tool development flow chart:

Naked eye-magnifying glass-optical microscope-electron microscope-scanning tunneling microscope.

Unit 2 Material Change

1, the world is made up of (matter), all matter is constantly (changing), and the change of matter is different, fast and slow. Some changes only change the state, shape and size of matter, but do not produce new matter different from the original. We call such changes (physical changes), and some changes produce (new substances).

Material changes in the world around us are generally divided into two categories, namely, (physical changes) and (chemical changes). There are many phenomena related to chemical changes, and the most important feature is (producing new substances). Physical changes must have taken place in the process of chemical changes of substances.

3. Some substances will not produce new substances after mixing, such as (sugar) and (water); Some substances will produce new substances after mixing, such as (baking soda) and (white vinegar)

4. Rice becomes (sweet) during chewing because there is something called (starch) in rice, which changes during chewing.

5. Starch will turn blue when it meets iodine, producing a new blue substance.

6, baking soda and vinegar mixed to produce a large number of (bubbles), generate a new gas, this gas can make the burning wood out, indicating that this gas (does not support combustion).

7. The chemical change process of substances is often accompanied by various phenomena, such as (luminescence and heat generation), (gas generation), (color change) and (sediment generation).

8. Rust is related to water and air. In daily life, the speed of iron rusting has a great relationship with (water quantity).

9. A hypothetical experiment to explore which factors are related to rust:

(1) Research question: Is rust related to water and air?

(2) Our hypothesis: rust is related to water and air;

(3) Experimental materials: three plates, three nails, water and vegetable oil;

(4) Experimental method: Put three nails in three plates, two of which are filled with water and vegetable oil respectively;

(5) Experimental phenomenon: The nails placed in the empty dish in contact with air are a little rusty, while the nails placed in the water dish in contact with water and air are more rusty, and the nails immersed in the vegetable oil dish have not changed;

(6) Experimental results: Rust is related to water and air, among which water plays a more important role.

10, clamp the nail with tweezers and immerse a part in copper sulfate solution. After a while, when the nails are taken out, it can be found that there are (new substances attached) on the surface of the nails soaked in the solution, and the color of the blue copper sulfate liquid will be (lighter), which belongs to (chemical change).

1 1. Take out a spoonful of white sugar with a long-handled metal spoon and put it on a candle flame to heat it slowly. White sugar will undergo physical changes (melting) and chemical changes (carbonization).

12, baking soda and white vinegar are mixed to produce (carbon dioxide) gas.

13. In production practice, what methods do people generally adopt to prevent and slow down the rust of iron products?

A:

(1) to make alloy;

(2) coating a protective layer on the surface of the iron product;

(3) Keep the surface of iron products clean and dry.

Unit 3 Universe

First, fill in the blanks:

1, the moon is the earth's (satellite), its radius is about a quarter of that of radius of the earth, its gravity is one sixth of that of the earth, its volume is one forty-ninth of that of the earth, its mass is one eightieth of that of the earth, its average distance from the earth is about 380,000 kilometers, and the temperature difference between day and night is (3 10℃).

2.1In July 1969, the American manned spacecraft (Apollo 1 1) landed on the moon successfully. The first man to land on the moon was an American (Armstrong).

Most of the craters on the moon are (circular), some are (single), some are (stacked together), and some are (big ring and small ring). In the speculation of the formation of lunar craters, the accepted view is (meteorite impact theory).

The moon rotates counterclockwise around the earth (from west to east).

The moon is a (unlit) (opaque) sphere, and the moonlight it sees is the light it reflects (the sun).

6. The various shapes of the moon during the alternation of the moon and the moon are called (moon phases). The moon phase is actually the part of the moon that people see from the earth that is illuminated by the sun.

7. Moon phase diagram:

The first day, the fourth day, the eighth day, the twelfth day, the fifteenth day, the eighteenth day, the twenty-third day and the twenty-seventh day.

In ancient times, people had a special name for the moon phase. The "first day" is called (new moon) and the "fifteenth day" is called (full moon).

9. The change law of the moon phase in a month is (in the first half of the month, it turns from missing to round, and the light is on the right; The second half of the moon lacks a circle, and the tooling is on the left).

10, there are three kinds of solar eclipses (total solar eclipse) (partial solar eclipse) (annular solar eclipse), and only two kinds of lunar eclipses (total lunar eclipse) (partial lunar eclipse); The solar eclipse occurs on the first day of the lunar calendar, and the lunar eclipse occurs on the fifteenth or sixteenth day of the lunar calendar.

1 1. When the moon moves between the sun and the earth, if the three are in a straight line, a solar eclipse will occur. When the moon moves to the back of the earth, if the three are in a straight line, an eclipse will occur.

12. The solar system is a celestial system centered on (the sun), including (eight planets and their satellites), (dwarf planets) and (small celestial bodies) "including asteroids, meteors and comets". The average distances from these planets to the sun are (Mercury), (Venus), (Earth), (Mars), (Jupiter), (Saturn), (Uranus) and (Neptune).

13, people divide the stars that seem to keep the same distance from each other into a group, into different regions, and name them after the shape of (people, animals or other objects). People call these areas (constellations). One of the constellations is particularly famous for its meteor shower. This constellation is Leo.

14. The obvious sign of Ursa major is the seven bright stars (the Big Dipper) that we are familiar with. There is a famous (Polaris) in Ursa minor in the northern sky.

15, "Summer Triangle" refers to Tianjin IV (Cygnus), Vega (Lyra) and Altair (Eagle).

16, the shining galaxy belt in the sky is actually a group of stars composed of (100 billion-200 billion), called (Milky Way), and its diameter is about (100 billion light years). The Milky Way is not the whole universe. There are (1000 billion) galaxies like the Milky Way, which people call (extragalactic galaxies).

17, the speed of light propagation is 300,000 kilometers per second, and (light years) is the distance that light travels in one year.

18, China is recognized as the birthplace of rockets in the world, which appeared in ancient books more than 700 years ago (Three Kingdoms period).

19, China's space technology occupies an important position in the world. The (Shenzhou) spacecraft realized China's dream of flying, and the (Chang 'e-1) lunar exploration satellite was successfully launched. In the future, Chinese astronauts will go to the moon.

20. Formation of solar eclipse: When the moon moves between the sun and the earth, if the three are in a straight line, the moon will block the light from the sun to the earth. People in the shadow on the earth can only see part of the sun completely, and the solar eclipse occurs.

Three-sphere position map during solar eclipse formation;

The sun, the moon and the earth

Unit 4 Environment and Us

1, people produce a lot of (garbage) in their lives. Discarded garbage (harmful to the environment). At present, the main ways of garbage disposal are (landfill) and (incineration), and simple landfill and incineration will also cause environmental pollution.

2. Landfill can be on it (building parks and stadiums), but not on it (building houses and planting crops).

3. (reducing the amount of garbage) is the way to solve the garbage problem from the source.

4. (Overpackaging) will cause (waste of resources) and produce a lot of garbage, and the abuse of plastic bags will also cause (environmental pollution).

5. (Reuse) refers to using the used goods for many times or in another way, which is also an important way to reduce garbage.

6. Garbage can be divided into kitchen waste, recyclable garbage, toxic harmful waste and other garbage. Domestic garbage can generally be divided into recyclable garbage, kitchen waste and other garbage.

7. Kitchen waste includes: peels, leftovers, etc. Recyclable garbage includes: paper products, metal products, plastic products, glass products and rubber; Toxic and harmful wastes include expired drugs, syringes, waste batteries, waste fluorescent tubes and waste water silver thermometers; Other rubbish includes: bricks and tiles, ceramics, toilet waste paper.

8. To effectively recycle garbage, we must change the habit of garbage (mixed loading) and carry out domestic garbage (classified and repackaged) to facilitate the treatment of toxic garbage. Waste batteries and medical wastes are wastes that need to be treated carefully.

9. (Composting) can effectively reduce garbage and form (fertilizer).

10, China is a country short of water resources, with the total water resources ranking sixth in the world and the per capita water resources ranking 1 10, which is listed as one of the 13 water-poor countries by the United Nations. There are more than 100 countries in the world that are seriously short of water, among which more than 40 countries are the most serious.

1 1. The pollution source of water may come from (agricultural sewage), (industrial sewage), (domestic sewage), or from animal carcasses. It can be seen that water pollution is mainly caused by human activities.

12. The tap water sources in most areas come from (reservoirs), (lakes) and (rivers). Tap water is the main source (drinking water), and (drinking water source) cannot be polluted.

13, sewage treatment is more complicated, generally through three methods, namely (precipitation), (filtration), (sterilization) to get purification.

14. The environmental problems we are facing are (air pollution), (white pollution) and (accelerated extinction of species).

15, (indiscriminate hunting by human beings) and (over-exploitation and utilization) make many biological resources on the verge of exhaustion.

16 (establishing nature reserves) is an effective way to protect biodiversity. China has established nature reserves in (Jiuzhaigou), (Changbai Mountain) and (Wolong, Sichuan).

17. Advantages and disadvantages of landfill and incineration: landfill mode: advantages (more convenient, lower cost) disadvantages (land occupation, slow decomposition of garbage, which may pollute groundwater); Incineration method: advantages (less land occupation, avoiding groundwater pollution and using heat) disadvantages (consuming electric energy, possibly causing secondary pollution)

18. The gas related to global warming is mainly (carbon dioxide); Sulfur dioxide produced by burning fossil fuels (oil, natural gas and coal) is the main cause of acid rain.

19, the ways to reduce garbage are:

(1) Reduce discarding;

(2) reuse;

(3) recycling.

20, please make a family water saving plan:

(1) Wash hands and wash basins;

(2) Taomi water is used to wash dishes;

(3) shower water is used for flushing toilets; Fish water is used to water flowers and plants; Use water-saving appliances, etc.

2 1. Suggestions on the management of natural waters in my hometown: (3)

22. Talking about environmental protection measures: (3)

23. What will you do to reduce the environmental problems of "white pollution"? A: Bring your own shopping bag when shopping; The store gives less plastic bags; Reuse existing plastic bags; Bring a vegetable basket and a cloth bag when buying food; Bring your own tableware when dining at work or school; Go out to eat and use less plastic fast food boxes. Collect waste plastic products and sell them to waste purchasing stations for recycling and refining.

The ozone layer in the earth's atmosphere is the protective umbrella of the earth and is called "the armor of the earth".

25. 1972 The slogan of the Declaration on the Human Environment adopted by the first United Nations Conference on the Human Environment is "There is only one earth".

Connection problem

1, physical change:

The bread is moldy.

Iron rusts.

The water froze.

Chemical changes:

Baking soda mixed with white vinegar

Match burning

Nail bending

2. Associate the following names with their contributions.

Yuan Longping

Antoni van Leeuwenhoek

Robert Hooke

Pasteur

bacon

The first to discover and put forward the name "cell"

Using microscopic technology to improve rice and cultivate hybrid rice.

He was the first to point out the relationship between microorganisms and human health.

Design and manufacture glasses that can improve eyesight.

To make a microscope with metal structure, it can be magnified 300 times at the earliest.

3. Connect the tentacles and shapes of the following insects with lines:

Silkworm moth stick

Anoplophora longicorn filiform

Butterfly whip

Ant feather

Locust knee

Drawing: draw a picture of onion epidermal cells under a microscope;