Will a parachute slow a skydiver more at a very high altitude or a lower altitude?

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

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?

What is the chemical formula for the compound formed between sodium and flour one