Can someone plz help? Thanks so much! An atom that contains 6 protons 6 neutrons and 6 electrons has a mass of approximately
1) 12 u
2) 12 g
3) 18 u
4) 18 g

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. an industrial chemist studying this reaction fills a 25.0l tank with 4.5 mol of sulfur dioxide gas and 4.5 mol of oxygen gas at 30.°c. he then raises the temperature, and when the mixture has come to equilibrium measures the amount of sulfur trioxide gas to be 1.4 mol. calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. round your answer to 2 significant digits.

Drug abuse will not lead to physical and psychological dependence. true or false ?