Unit 2 Chemistry

What’s in a square?

Different periodic tables can include various bits of information, but usually: atomic number symbol atomic mass

Atomic Number The atomic number refers

to how many protons an atom of that element has.

For instance, hydrogen has 1 proton, so it’s atomic number is 1.

No two elements have the same atomic number.

Charge

For neutral atoms (no charge) protons= electrons

Symbols All elements have their

own unique symbol. Elements have their name

for a variety of reasons. Some are named after mythology, countries, scientists or in Latin or Greek.

C Carbon

CuCopper

Atomic Mass

Atomic Mass refers to the “weight” of the atom.

It is derived at by adding the number of protons and the number of neutrons.

This is a helium atom.

What is its atomic mass?

Atomic mass= protons+ neutrons(electrons have such small mass that they

don’t contribute to the weight) Neutrons= atomic mass - protons

Atomic Mass Unit (AMU)

The unit of measurement for an atom is an AMU. It stands for atomic mass unit.

One AMU is equal to the mass of one proton.

Assignment

Elements and their structure A World Famous Table Which atom is which