What is the complete ionic equation?

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Which substance is a steroid? cholesterol fatty acid monosaccharide trans fat

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?