Which statement is true about the substances present in a mixture? They always consist of the same element.
They are always in the same state of matter.
They can be separated by physical methods.
They can only be separated by chemical methods.

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.

In 2002, the rare earth elements mine in mountain pass, california was closed because

What is true for a substance that releases energy