Please help me out with this...please

I also put the periodic table too just in case:)

Why are the trends and exceptions to the trends in ionization energy observed?

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.

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?