input: OPTIONS:
- insulators
- bases
- sealants
- catalysts Now, answer this question: Q: Many transition metals and their compounds are used as what? A:
A:
output: catalysts

Q: What forms when an atom gains electrons? A:

OPTIONS:
- cations
- bonds
- crystals
- anions

Answer: anions

Problem: OPTIONS:
- pheromones
- enzymes
- acids
- hormones
Q: Q: What is another term for chemical messenger molecules? A:
Answer: hormones

Problem:OPTIONS:
- carbon composition
- mineral composition
- density
- chemical composition

Q: Minerals are grouped based on what? A:
****
A: chemical composition

Q: What is a rigid layer that surrounds the plasma membrane of a plant cell? A:
OPTIONS:
- the nucleic wall
- the cell center
- mitochondria
- the cell wall
the cell wall

Q: What attracts the earth to the sun? A:
OPTIONS:
- weight
- light
- the moon
- gravity

Answer:
gravity