Can someone help please

What is the maximum number of electrons that an atomic orbital can contain?

According to periodic trend, which of the following most likely has the highest ionization energy? kr be ni sc

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.