How much water is stored in polar ice caps glaciers and permanent snow

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.