1. Atomic Structure

2. Atomic Structure
Identify the following structures and subatomic particles.
Neutron
Orbital
Also called the electron path, electron cloud, or energy level. +
Atom
Nucleus +
The basic unit of matter
Proton (+)
Electron (-)
An electron has 1840 times less mass than a proton

3. Atomic Structure
If the nucleus of an atom were the size of a bb, the nearest electron would be about 370’ away.
Hence: Atoms are mostly empty space. +
Nucleus +
A teaspoon of nucleus weighs about 1 trillion pounds.
Hence: Atomic nuclei are very dense (3.6 trillion pounds / in3)

4. Isotopes of Hydrogen Protium Deuterium Tritium Atomic number 1 1 1
Electron (-)
Neutron
Proton (+) + + +
Atomic number 1 1 1
(No. of protons)
Mass Number 1 2 3
(Protons + Neutrons)
Atomic Mass
Relative abundance
99.985%
0.015%
1 x %
1/6,700
1/quintillion

5. Hint: Isotopes always have the same number of protons.
Atomic Structure
Helium +
Which of the three atoms below is an isotope of the one to the right?
Hint: Isotopes always have the same number of protons. A B C + + + + + +
Lithium
Hydrogen
Helium