<span>substances consisting of ions held together by electrostatic attraction
</span>
The answer is Helium. hope its helpful (:
Answer:
Orbitals
Shells
Energy Levels
Explanation:
Elements in the same period will have the same energy levels which is the same as orbitals and shells.
- The period of an element indicates the energy level in an atom.
- Elements in period 1 will have one energy level or shell or orbitals.
- Down a group this is not the case.
- The energy level increases from top to bottom.
- As we go down the group, we are transiting from one period to another.
Answer:
B: They are the results of many experiments over a long period of time.
Explanation:
