Refer to the periodic table and state the atomic mass (in amu) of one atom for each of the following nonmetals: carbon,sulfur,selenium and iodine

Question #1) Refer to the periodic table and state the atomic mass (in amu) of one atom for each of the following nonmetals: carbon,sulfur,selenium and iodine.

Question #2) State standard conditions for a gas in Kelvin units and atmosphere

Question #3 How many moles of barium metal react to produce 0.100 mol of barium nitride? How many moles of nitrogen gas react?   Ba(s)+N2(g)  -->    Ba3N2(s) (two is supposed to be lower case)

#4) Classify the type of stoichiometry problem: How many grams of baking soda must decompose to give 25.0ml C02 gas?