there about 5000 elements, which combine to form the vast number of diffrent substances in the world around us

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?

If an atom has 12 protons and 13 neutrons

Which method would be best to separate a mixture of sand and gravel