intro 1
Across
- 4. a substance made by combining two or more than two metals to resist corrosion
- 5. a chemical that are used to prevent wastage of food by microbial growth
- 6. a person who studies and gains specialization in chemistry
- 7. a naturally occurring substances from which metals were extracted
Down
- 1. Chemicals that are used to protect the crops from harmful pests
- 2. a Scottish scientist who discovered nitrogen
- 3. chemical preparations that provide immunity from a disease