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