When electrons are filling energy levels, the lowest energy sublevels are occupied first. This is Hund's rule.
Hund's rules state that:
Every orbital in a sublevel has to be singularly occupied before any other orbital is able to be doubly occupied.
All of the electrons in single occupied orbitals have to have the same spin to maximize the total spin.
Friction of the air, and the surface it is on
Explanation:
here is the answer. Feel free to ask for more chem help
Alpha particles are helium nucleus ! so answer is A !
it is made by ionization of helium, when both the electrons are out , then two unit of positive charge is one helium and thus called alpha particle !
