Is the fractional distillation of liquefied air a physical or chemical change?

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. : )

During chemistry class, carl performed several lab tests on two white solids. the results of three tests are seen in the data table. based on this data, carl has concluded that substance b must have bonds.

For the following, determine the type of reaction and then give products.