HOMEWORK! What do these mean?

Reactants undergo chemical reaction to form products. this chemical equation represents one such reaction. the coefficient for one of the reactants or products is incorrect. which part of the chemical equation is incorrect?

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons

What goes in and out of a cell respiration?