Which sequence of group 18 elements demonstrates a gradual decrease in forces of attraction

In the space, show a correct numerical setup for calculating the number of moles of co2 present in 11 grams of co2

Upon decomposition, one sample of magnesium fluoride produced 1.65 kg of magnesium and 2.56 kg of fluorine. a second sample produced 1.32 kg of magnesium. part a how much fluorine (in grams) did the second sample produce?

Carbon-14 undergoes radioactive decay in the reaction above. determine the type of radiation emitted in this reaction and describe what is happening to the nucleus during this reaction.