The type of change that occurs when a solid becomes a liquid is
physical
chemical
nuclear

1) how many electrons are in each energy level of the following elements? a. he b. na c. na d. ne 2) how many valence electrons are percent in the following atoms? a. s b. mg c. be d. cl 3) which of the following elements are stable as atoms? a. he b. o c. cl d. ar if you are able to provide the work as to how you got the answers that would be greatly appreciated. : )

At stp, what is the volume of 1 mole of co2?

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.