Structure of the Atom and Periodic Table

Proton

They have a positive charge and are located in the nucleus

Neutrons

Have no charge and sit inside the nucleus

Electron

Have a negative charge and spin around the nucleus in electron shells

What is the mass of a proton, neutron and electron?

• proton: 1

• neutron: 1

• electron: 1/1840

Isotope

contain the same number of protons but have different neutrons (still have equal numbers of protons and electrons)

Atomic mass

the number of protons and neutrons in the nucleus of an atom

What is the periodic law?

It states when elements are arranged in order of increasing atomic number, there is a periodic patter in their properties

What are the groups and periods

• groups are column and have similar properties because they have the same number of valence electrons

• periods are the rows

Describe metals

• Solid at room temp

• shiny

• good conductors

Describe metalloids

• have properties of both metals and non-metals

• shiny but brittle

• poor conductors

Describe non-metals

• dull

• poor conductors

• lower-melting point than metals