Is the mass of water greater than the mass of two gases

What elements have 2 electrons inthe 4s sublevel

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)

How many moles of potassium are needed to react completely with 12.8 moles of magnessium bromide?