Which of these is a balanced chemical equation? 2Ca + O^2 → 2CaO

Ca + O^2→ CaO

Ca + 2O^2 → 2CaO

2Ca + O^2 → CaO

An excess of lithium oxide undergoes a synthesis reaction with water to produce lithium hydroxide li2o+h2o→2lioh if 1.05 g of water reacted, what is the theoretical yield of lithium hydroxide? a) 5.83 x 10–2 g lioh b) 1.17 x 10–1 g lioh c) 2.79 x 100 g lioh d) 1.40 x 100 g lioh

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?

If a gas has an initial pressure of 101kpa and a volume of 10l, then it expands to a volume of 20l, what is the new pressure?