Explanation:
SOLID
Sodium hydroxide exists in the solid phase at room temperature. You would find it in the lab as hemispherical white solid pellets. The phase of a substance depends on temperature and pressure. As you heat a solid, it will melt and change to the liquid phase.
A catalyst
A catalyst can be in many forms
Answer:
B. To ask and answer scientific questions
Oxygen had 6 valence electrons
I think the answer is choice D