A characteristic of a substance that can be observed or measured.

Three physical properties of the beach glass below:

Lusture (shiny) Colour (red, green, blue) Transparency (how see through it is)

Describes the ability of a substance to change into a new substance or substances.

Chemical properties includes how a substance INTERACTS with other substances.

Eg. Acids, water, heat, combustibility

Physical Change: Changes affecting the form of a substance, but not its composition.

(cutting paper, grating cheese, melting ice, chopping wood)

Chemical Change: a change in matter that results in the formation of a new substance(s).

(cooking an egg, burning wood, metal rusting, copper oxidizing)

1. All matter is made of small, indivisible particles called atoms.

2. All the atoms of an element are identical in properties such as size and mass.

3. Atoms of different elements have different properties.

4. Atoms of different elements can combine in specific ways to form new substances.

All elements are composed of atoms, and one atom is the smallest unit of any element.

Protons - Positive charge - found in the nucleus

Neutrons - No charge - found in the nucleus

Electrons - Negative charge - found in energy levels surrounding the nucleus

Ions form when an atom obtains a FULL outer shell by either 'giving away' or 'taking' electrons.

1. All matter is made of small, indivisible particles called atoms

2. All the atoms of an element are identical in properties such as size and mass

3. Atoms of different elements have different properties.

4. Atoms of different elements can combine in specific was to form new substances.

He experimented with electric currents in glass tubes called cathode ray tubes. Found the electron. His model of the atom was a positive sphere with negative electrons scattered throughout it.

Rutherford conducted an experiment in which he shot positively charged particles at a very thin foil of pure gold. Based on his experiment he discovered the nucleus.

He calculated that the size of the nucleus compared to the rest of the atom was like the size of a single green pea compared to an entire football field!

Bohr studied the properties of electrons in atoms and helped to transform Rutherford's model into one of the models that is used today.

He suggested that electrons surround the nucleus in specific energy levels, called shells.

Metals

1. Most of the elements on the periodic table are METALS.

2. Excellent conductors of electricity and heat.

3. Most are shiny and a silver or grey colour.

Non-Metals

1. Grouped together mostly because they do not resemble metals.

2. Not good conductors of electricity/ heat.

Metalloids

1. Have metallic and non-metallic properties.

2. Are generally 'semi-conductors' (conduct some electricity, but not very well)

PLEASE REVIEW YOUR NOTES for the characteristics of each family.

1. Number of valence electrons for each group.

2. Number of electron shells

3. Valence number (+1, +2, +3, +/-4, -3, -2, -1)

4. Reactivity (Group 1 is HIGHLY reactive, Nobel Gases are un-reactive)

Ionic compounds are PURE SUBSTANCES that consist of at least one metal and

one non-metal. When two atoms combine, both atoms change into an ion (they both have full outer shells). - see pictures below

When non-metals combine, a pure substance is formed called a molecular/covalent compound.

These molecules SHARE electrons so that they can have a complete outer shell.

ex. Sodium and Chlorine (NaCl)

Name the Metal + Name of non-metal + ide = Sodium Chloride

Step 1: Write down the element symbols

Step 2: Write the valence number above both symbols

Step3: "Criss-Cross" the numbers down

Step 4: Reduce or "simplify" if possible

(see example below)