The changes of chemical reactions include:
举一反三
- Over 100,000 chemical reactions _____ the brain every second.
- In chemical reactions, all electrons rearrange around the nuclei.
- All chemical reactions in the body are catalyzed by enzymes. A: 正确 B: 错误
- 以下表达“自然变化”的英语词汇是_______。 A: toxic chemicals B: chemical industry C: chemical changes D: natural changes
- Enzymes speed up chemcial reactions by... A: lowering activation energy. B: increasing the activation energy needed. C: breaking the chemical energy needed. D: stopping the chemical reaction.