The aufbau principle, from the German Aufbauprinzip (building-up principle), also called the aufbau rule, states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels.
Hey there! Here is the answer:
B.) decrease; increase
Here's why:
As you move from left to right across a period on the periodic table the size of an atom will decrease. As you move from top to bottom down a group on the periodic table the size of an atom will increase.
I really hope this answer helps you out! :)
<span>The balance format is
4NH3+ 5O2 -------> 4NO + 6H2O </span>