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CHEMISTRY
PERIODIC TABLE
100
This unit smallest form of an element.
What is an atom?
100
The last column of inert gases are called this.
What are Noble Gases?
200
A group of the same atoms are called this.
What is an element?
300
They orbit the nucleus ,of the atom, up to two in a orbit.
What are electrons?
400
The Electron Energy Level for the two electrons closest to the nucleus is represented by this letter and two numbers.
What does 1s2 represent for electrons, around the nucleus of an atom?