Help me please I really need this to be answered

What is the lowest number energy level where a d sublevel is found

What must be in balance for temperatures to remain constant?

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium.b)heavier than helium.c)the same weight as helium.d)dependent on the element that reacted with carbon.