In a chemical equation, the number written in front of the chemical formula is the

True or false, the three major scales used to measure earthquakes are mercalli scale, richter scale and magnitude scale

What are the similarities of physical and chemical change ?

For the reaction shown, find the limiting reactant for each of the following initial amounts of reactants. 4al(s)+3o2(g)→2al2o3(s) a) 1 molal, 1 mol o2 b) 4 molal, 2.6 mol o2 c) 16 molal, 13 mol o2 d) 7.4 molal, 6.5 mol o2