Quick Write

• What is an atom?

• What is an element?

Atoms and Elements

• All matter is made up of atoms.

• Matter that is made of ONE type of atom is called an element.

• For example: The smallest amount of gold you can have is 1 gold atom.

Periodic Table of Elements

Chemical

Atomic structure

Atomic Structure

• Atoms are made of 3 particles:

Name of particle

mass charge location

Proton 1 amu Positive Nucleus

Electron Insignificant(very small)

Negative Electron cloud

Neutron 1 amu Neutral Nucleus

Periodic Table of Elements

• Different types of atoms have different numbers of particles.

• An atom is identified by the number of PROTONS it has. The number of protons is the atomic number.

• Each element is made of atoms with a specific number of protons.

How are atoms different?

Chemical

Isotopes

• Atoms of a specific element have the same number of protons and electrons, but they can have different numbers of neutrons. This is called an isotope of that element.

• For example: Carbon has 6 protons and 6 electrons. It usually has 6 neutrons but sometimes has 8, then it is called carbon 14 because it has an atomic mass of 14.

What is the chemical symbol and atomic number of the following elements?

• Hydrogen• Silver• Sulfur• Chlorine• Zinc

• Aluminum• Oxygen• Magnesium• Neon• Mercury