What is the electron configuration of an Fe2+ ion?

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

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)

An unknown insoluble substance displaced the water shown. it's mass is indicated on the triple beam balance. mass = a. 694 b. 693.5 c. 693.0 d.693.8