While looking out the window, you see lightening flash and then 3 seconds later, you hear the thunder. how far was the lightening from you?

a. 3,300 ft

b. 3 miles

c. 300 ft

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.

Consider the elements bromine and chlorine; which elements has a larger ionic radius ?

How are isotopes of the same chemical element alike? how are they different?