What percentage do the elements hydrogen and helium account for in the universe? A. 100% B. 99.9% C. 98% D. 99.8%

Which of the following would have the greatest reaction speed? A. A reaction with solid reactants under low pressure and with high surface area. B. A reaction in cold temperature and high surface area with gaseous reactants. C.

If an atom has 5 protons, how many electrons does it have?

Five years ago, my grandfather was five times as old as I was. Three years from now, my grandfather will be three times as old as I will be. how old am I now?

If you breathe normally you have about 0.11 moles of air in your lungs and a volume of 2.4 L. If you then take a deep breath all the way, you will have 0.27 moles of air in your lungs. How big will your lungs be?

Jim measures the side of a box and finds it to be 0.564 meters long. How long is it in centimeters a) 0.00564 b) 0.564 c) 5.64 d) 56.4

What does the cell theory state? A. that cells come from other cells B. that cells come only from animals C. that cells cannot be created or destroyed

For which one of the following molecules is the indicated type of hybridization not appropriate for M the central atom? a. BeCl2 sp2 b. SiH4 sp3 c. BF3 sp2 d. C2H2 sp e. H2O sp3

P4O10 (s) = - 3110 kJ/mol H2O (l) = - 286 kJ/mol H3PO4 (s) = - 1279 kJ/mol Calculate the change in enthalpy for the following process: P4O10 (s) + 6H2O (l) → 4H3PO4 (s)

Aluminum bromide reacts with chlorine gas to produce aluminum chloride and liquid bromide, according to the chemical equation below: 2A1Br3 + 3Cl2 + 2AlCl3 + 3Br2 How many moles of Aluminum chloride are made if 779 g of chlorine gas are consumed?

When a cell is in late anaphase of mitosis, which of the following will we see?