What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valenc electron? energy mass neutrons electrons

## Step 1<br />The problem is asking what can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron. <br /><br />## Step 2<br />Valence electrons are the electrons in the outermost shell of an atom. They are the electrons that participate in chemical bonding. <br /><br />## Step 3<br />Adding energy to an atom can cause an electron to move from a lower energy level (closer to the nucleus) to a higher energy level (further from the nucleus). This process is known as excitation. <br /><br />## Step 4<br />When an electron is excited, it can move to a higher energy level, which is further from the nucleus. This means it has become a valence electron. <br /><br />## Step 5<br />The other options, mass, neutrons, and electrons, do not have the same effect. Adding mass or neutrons to an atom would change the atom's identity, not the energy level of its electrons. Adding more electrons would increase the negative charge of the atom, but it would not change the energy level of the electrons.