Chemistry 1100 (EXAM 1) - Mizzou

Matter

- Takes up space

- Has mass

- Either a Solid, Liquid, or Gas

Atoms

- Building Blocks of matter

- 118 (known) atoms

- Reactants > Compounds

The Periodic Table

Purpose: Organize elements by atomic number and by atomic mass.

- Rows are Periods

- Columns are Groups (share similar chemical properties)

periodic means repeating pattern

Group 1A Name:

Alkali Metals

Group 2A Name:

Alkaline Earth Metals

Group 5A Name:

Pnictogens

Group 6A Name:

Chalcogens

Group 7A Name:

Halogens

Group 8A Name:

Noble Gases

What kind of charge does a Proton have?

+1

What kind of charge does an Electron have?

-1

What kind of charge does an Neutron have?

0

Neutron

# of Protons = # of Electrons

What determines an elements identity?

The # of protons it has

Can an element contain a different # of electrons?

Yes. (Ions)

example: Na (11e-, 11p+) >(1e-) Na (10e-, 11p+)

Can an element contain a different # of neutrons?

Yes. (Isotopes)

example: 3 kinds of Carbon

6p, 6n, 6e - Carbon-12 (99% of all carbon)

6p, 7n, 6e - Carbon-13 (1% of all carbon)

6p, 8n, 6e - Carbon-14 (almost 0% of all carbon)

(radioactive)

Atomic Number (Z)

# of protons in nucleus

Mass Number (A)

# of protons + number of neutrons = (Z) + # of neutrons

Isotopes:

same element (X) with different numbers of neutrons

How to write Mass Number/Atomic Number and Element

What happens if you change the # of protons in an element?

It changes the identity of the element.

What happens if you change the # of neutrons in an element?

It changes it to an Isotope.

What happens if you change the # of electrons in an element?

It changes to an Ion

Classification of Matter

Gases, Liquids, Solids, Plasma = Matter

What are elements?

On the periodic table, expressed by a chemical formula

What are compounds?