一、以弹簧振子为例

1 Light waves and the coherent condition of waves 1. Light waves Light wave is a small part of the whole electromagnetic wave spectrum. Wavelength (m) 102

Chemical reactions happen in nature to produce natural substance, and even living organism. Chemical reactions have been used by us to produce millions of substance that do not exist in nature. Chemical reactions are the central part of the chemical sciences

3.1 Chemistry developed out of interest in materials The ability to control fire allowed ancient people to prepare copper(7000 years ago) and iron (3200 years ago) for tools and weapons

Acid-base reaction: Transfer of proton Oxidation and reduction: transfer of electron

10.1 Acids donate protons, bases accept them Sulfuric acid is the number one manufactured chemical 85 billion pounds (40,000,000tons) annually in US. Acid has “sour taste

Chapter 1 Chemistry is a Science of Change water molecule is consisted of one oxygen(氧) atom and two hydrogen(氢) atoms A cup of water contains about 1024 water molecules

The atmosphere layer is very thin compared to the size of the Earth

Golden rice: two European scientists created a new strain of rice enriched in B-carotene, which the body uses to make vitamin A. This is a kind of transgenic plant(转基因植物)

I. Choose the Correct Answer 1. Which statement is most correct? (C) (A)Uniform circular motion causes a constant force toward the center. (B)Uniform circular motion is caused by a constant force toward the center