There are 8 of these in the Periodic Table, not including the transition metals.
What are groups or families?
The two subatomic particles that are always found in the same number when looking at the Periodic Table.
What are protons and electrons.
The most reactive nonmetals
What are Halogens
The outer orbital of where atoms form bonds.
What is the valence shell?
This is how the original Periodic Table of Elements was first organized.
What is by atomic mass and chemical properties.
I am a gas- my properties are so unique, and I'm very different from other members of my family. I have my own separate space on the Periodic Table. I was also the end of the Hindenburg because I'm so flammable.
What is hydrogen?