Can someone help me out with the question

In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. part a write a balanced chemical equation for this reaction. express your answer as a chemical equation. identify all of the phases in your answer.

Concerning the 10.0 ml of 0.50 m nacl to 100 ml of solution: when a solution is diluted, does it change the number of moles dissolved?

How is 0.00235 expressed in proper scientific notation? a. 2.35 × 10-3 b. 0.235 × 10-2 c. 2.35 d. 2.35 × 103