First unit
1. In our sense organs, the eyes can collect more information than other senses, but people's highest vision can only see 1/5mm tiny objects.
2. Magnifier is also called convex lens. It can be magnified because the light in the air will be refracted and bent when it enters the magnifying glass.
The objects under the magnifying glass are not only magnified, but also see some details, such as pictures in newspapers, screens of computers and televisions, which are originally made up of many points, and the points they see are made up of red, green and blue.
Absorbent paper fibers are long, thick and loose.
Cylindrical and spherical transparent containers also have the function of magnifying glass when filled with water.
3. The magnification of a magnifying glass is related to the convexity of the mirror. The greater the convexity, the greater the magnification.
The transparent body magnification of the sphere is the largest.
With the increase of magnification of magnifying glass, not only the image of the observed object will become larger, but also more object information will be obtained, and the field of view will become smaller.
The area or area seen through the lens is called the field of view of the lens.
4. Calculation of magnification:
Like ants, locusts and silkworms, the body is divided into three parts: head, chest and abdomen. There are a pair of tentacles on the head and three pairs of feet on the chest, which are called insects.
Insects have many special structures and abilities. Dragonflies, flies and butterflies all have compound eyes.
Insects are one of the smallest animals visible to the naked eye in nature.
The natural enemy of aphids is Chrysopa. We can see the limbs of aphids under the magnifying glass of 10 times.
6. Common crystals include white sugar, salt, alkaline noodles and snowflakes. Most of them are regular shapes.
Methods of making crystals: water reduction method and cooling method.
7. Born in the Netherlands, Levin Hooke is a biologist who made the world's earliest metal structure microscope with a magnification of nearly 300 times.
A lens facing a small focal length object is called an objective lens (closer to the measured object). The focal length of the lens facing the human eye is greater than that of the eyepiece.
Electron microscope can magnify an object 2 million times, and both Escherichia coli and SARS virus can be observed by electron microscope.
8. The fine structure of an object must be made into a slide specimen to be clearly observed under the microscope.
Slices of slide specimens must be thin and transparent.
Many bacteria gather together to form colonies.
9. Organisms are all made up of cells.
British physicist Robert? Hook was the first person to discover and put forward the name "cell".
The establishment of cell theory is considered as one of the three major discoveries of natural science in the19th century.
The secret of drought tolerance of gem flower lies in its few pores. The green water in the fish tank is the function of green algae.
10. Before the invention of the microscope, human beings relied on the five sensory organs of eyes, ears, nose, tongue and body to explore and understand the world.
The invention of magnifying glass and microscope opened the door to the microscopic world for mankind.
Not all microorganisms are harmful to human beings. Many microorganisms are not only beneficial to human beings, but also indispensable to us!
French scientist Pasteur was the first to point out that microorganisms are related to human health.
Using the function of microorganism, we can make wine, vinegar, pickles, fermented bean curd, yogurt and other foods with unique flavor.
The inside of steamed bread and bread is porous because before steaming steamed bread or baking bread, yeast is added to the dough, which decomposes the sugar in the dough, thus obtaining nutrition and energy and discharging carbon dioxide. Humans have used yeast to make dough for more than 5000 years, which can make bread loose and porous.
Microorganisms in the soil can decompose the carcasses and residues of animals and plants.
Second unit
1. There are many ways to classify garbage. According to materials, it can be divided into plastic, metal, paper, glass and so on. And according to the hazard status, it can be divided into harmful waste and general garbage. ...
2. Domestic waste generated in daily life is solid waste, including construction waste, agricultural waste and industrial waste.
3. The influence of garbage on the environment is various, it will give off stench and pollute the air; Breeding mosquitoes and flies, causing diseases; It will also destroy the soil and affect agriculture.
4. At present, the general disposal methods of garbage are landfill, direct incineration and composting.
5. Clean landfill and natural composting have their own advantages and disadvantages.
Advantages: it can effectively reduce the pollution of garbage to groundwater, soil and air;
Disadvantages: environmental pollution can not be eradicated, occupying land.
6. When doing landfill simulation experiment:
Primary water is equivalent to groundwater;
Stone and sand are equivalent to soil layers;
Paper towels dipped in ink are equivalent to landfill;
Spraying water is equivalent to rain;
The discoloration of water is equivalent to the leakage of harmful substances and pollution of groundwater.
After landfill, parks and stadiums can be built on them, but they cannot be used to build houses and grow crops.
7. Reducing the amount of garbage is the way to solve the garbage problem from the source.
Reuse refers to using used things in another way, which is an important way to reduce the amount of garbage.
When we can't reduce the use of some materials, we can recycle these raw materials and reuse them, which can not only reduce the amount of solid waste, but also save a lot of natural resources.
The systematic scheme to solve the garbage problem should include: garbage reduction, recycling and harmless treatment.
Draw a universal recycling sign:
9. The reduction, reuse and recycling of solid waste are widely used in the world, which is the most active and scientific means to deal with waste at present.
10. In order to truly turn garbage into resources, garbage must be classified and repackaged.
Domestic garbage can be divided into recyclable garbage, kitchen garbage, other garbage and (toxic harmful waste).
Recyclable garbage includes paper, plastic, metal, glass, rubber, textiles and so on.
About13 of domestic waste is food waste such as broken vegetable leaves and eggshells. These garbage, dead leaves and weeds in the yard can be naturally decomposed by accumulation and become useful organic fertilizers. (Kitchen garbage)
1 1. Hazardous wastes include waste batteries, waste fluorescent tubes, waste water silver thermometers, syringes, expired drugs, etc. These wastes need special safety treatment. If buried underground, it will pollute the soil and groundwater; Burning will pollute the atmosphere. If people are affected by toxic and harmful wastes, they will suffer from various diseases and even endanger their lives.
12. In addition to the garbage problem, the world is also facing environmental problems such as water shortage, climate warming, species extinction, ozone layer destruction and land desertification.
At present, 60% of the mainland is short of fresh water resources, and 100 countries are seriously short of water, among which more than 40 countries are seriously short of water.
Land desertification has become the "number one killer" of global ecology.
The ozone layer in the earth's atmosphere is the umbrella of life on earth.
Human consumption of fossil fuels will increase the concentration of carbon dioxide in the atmosphere and raise the temperature of the earth's surface.
Many environmental problems are caused by human activities, but human activities can also improve the environment.
Third unit
1. The moon is a satellite of the earth. It revolves around the earth, and the directions of revolution and rotation are from west to east.
The diameter of the moon is about 1/4 of that of the earth. The mass of the moon is about 1/80 of that of the earth.
The volume of the moon is about 1/49 of that of the earth.
The gravity of the moon is about 1/6 of that of the earth.
1In July, 1969, the American "Apollo 1 1" manned spacecraft successfully landed on the moon, and astronaut Armstrong printed the first human footprint on the moon.
2. The various shapes of the moon during the change of the circle are called moon phases.
The moon phase changes regularly: in the first half of the month, it changes from lack to round, and in the second half, it changes from lack to round.
The biggest feature of the terrain is that there are many large and small craters. The name crater was named by Galileo.
At present, the accepted view of crater is "impact theory"
4. Reasons for the 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 and cast its shadow on the earth. People in the shadow on the earth can only see part or all of it, so there is a solar eclipse.
Eclipses usually occur on the first day of the lunar calendar.
There are three kinds of eclipses: total solar eclipse, partial solar eclipse and annular solar eclipse.
Draw the position relationship between the three during the solar eclipse:
Eclipses usually occur on the fifteenth day of the lunar calendar. Eclipses only occur at full moons.
Eclipses include total solar eclipse and partial solar eclipse.
Draw the position relationship between the three during the solar eclipse:
5. A celestial system with the sun as the center and including eight planets, satellites, dwarf planets, asteroids and comets rotating around objective existence is called the solar system.
The sun is the only shining star in the solar system.
The order of the distances from the eight planets to the sun is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
The largest planet is Jupiter and the smallest planet is Mercury.
Venus has the longest rotation period and Jupiter has the shortest rotation period.
Period of revolution of Neptune is the longest, and period of revolution of Mercury is the shortest.
6. There is a famous Polaris Ursa minor in the northern sky, which is not very bright. We can find Polaris with the help of Ursa Major.
The most obvious symbol of Ursa major is the familiar Big Dipper, which consists of seven bright stars.
The star in the head of Leo is like a question mark written backwards, and the three stars at the tail form a big triangle, which is the obvious symbol of Leo.
7. The shining galactic belt in the sky is actually a group of stars composed of many stars, called the Milky Way.
The Milky Way consists of about 654.38+00 billion to 200 billion stars with a diameter of 654.38+00 billion light years.
Light travels at a speed of 300,000 kilometers per second. A light year is the distance that light travels in a year. It is a unit used to measure the distance between stars.
At present, human beings have discovered more than 654.38+0 billion extragalactic galaxies.
China is recognized as the birthplace of rockets.
On October 25th, 2003/KLOC-0, Shenzhou 5 manned spacecraft was successfully launched. Astronaut Yang Liwei went into space.
On June 65438+1October 65438+February, 2005, Shenzhou VI once again carried the astronaut fee and Nie Haisheng into space.
In the process of exploring the universe, 14 people have given their lives. The American Challenge exploded during the launch, killing seven astronauts.
Fourth unit
1. How do scientists explore:
(1) The course of a scientist's exploration of a problem: observation and discovery-asking research questions according to his own knowledge background-using previous research results-proposing possible explanations-using technical and mathematical methods to collect evidence-forming his own explanation-collecting new evidence-supplementing the original explanation-publishing research results.
(2) Scientific inquiry is not a linear process, but a process of constantly asking questions and constantly verifying.
The process of finding evidence is the process of collecting information and processing it.
(3) In the process of scientific research, we are also constantly experiencing the process of scientific inquiry by scientists.
2. How do we know:
(1) In scientific inquiry, first of all, we should obtain a lot of information through observation, social investigation and experimental operation.
(2) The more accurate and comprehensive the effective data information is, the deeper the scientific inquiry will be.
3. What I see and think:
(1) Collecting information with the senses is easy to add your own feelings, imagination and guesses, thus blinding the facts.
(2) Repeated experiments, multi-angle and multi-means observation and inspection by others can collect more factual information.
4. Access and identify information:
(1) You can get a lot of indirect information through books, newspapers and the Internet.
(2) The reliability of information can be distinguished by the time of information release and the way of obtaining information.
5. Recording and storage:
(1) With pen and paper, camera, video camera and computer, the obtained information can be recorded and saved for future research and use.
(2) With more and more information, more and more space needs to be stored. We should reduce the storage space of information and choose appropriate recording and storage media.
6. Organize the obtained information:
(1) The information obtained by sorting, comparing and contrasting can make the information more organized and clear.
(2) Classification chart, comparison/comparison table, line chart, flow chart, circulation chart and statistical chart are effective ways to organize information.
7. Exchange our information:
(1) Communication is a process of sharing information in scientific inquiry, which can help us correct our mistakes and get more information.
(2) The exchange of information requires us to be good at listening and express ourselves clearly, so as to exchange information quickly and accurately.
8. Send the message to more people:
(1) Pass the information to more people to enjoy through wall newspapers, exhibitions, newspapers, magazines, telephone, e-mail, internet and other ways.
(2) The transmission of information is inseparable from the development of information technology.