Atoms and the Periodic Table. Atoms are the basic building blocks of all matter. Atoms are made up of: Protons—Positively charged particles; found in the nucleus Neutrons—Particles that have no charge; found in the nucleus Electrons—Negatively charged particles; found outside the nucleus.
1st energy level containing two electrons
Pure Gold 18-Karat Gold 14-Karat Gold
two isotopes of Sodium
The first 2 electrons go in the 1st energy level.
The other 4 electrons go in the 2nd energy level.
If we have 6 protons in the nucleus, we need to have 6 electrons in the energy levels around the nucleus.
Next, you draw a dot for each electron in the outermost energy level. You can put dots on four sides of the symbol—top, bottom, left, and right. Put the dots in pairs.
First, you write the symbol for the element.