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
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
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)
Revision I. Expressions ss Directions: Turn the following English terms into Chinese without looking at your textbook 1. Purchase order: order sheet. order note indent