What type(s) of properties of a substance do not change with a change in amount or shape?
a) physical only
b) chemical only
c) physical and chemical

Which of the following can be used to measure electricity

Why is permeable soil best for plants that need a lot of drainage?

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?