What has more kinetic energy? 120 180, 105

How many grams of aluminum will there be in 98g of al2o3?

What was bohr’s contribution to the planetary model

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?