What is the total number of electrons in a s2– ion?
(1) 10 (3) 16
(2) 14 (4) 18

Compare and contrast physical changes with chemical changes.

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

If 3 moles of a compound use 24 j of energy in a reaction, what is the a hreaction in j/mol?