Introduction to Atomic Structure and Chemical Bonding

Rutherford Experiment

The results of the gold foil experiment led to the discovery of a very densely packed bundle of matter with a positive electric charge. Rutherford called this positive bundle of matter the nucleus. He was trying to figure something else out and accidentally discovered this. As much of a discovery as the gold foil experiment was, it wasn’t discovered intentionally.

Atomic Number

Consists of the number of electrons or protons.

Mass Number

Consists of the protons added to the neutrons.

Nonpolar Covalent Bond

A covalent bond in which the bonding electrons are shared equally by the bonded atoms. Example: H-H

Polar Covalent Bond

A covalent bond in which the bonded atoms have an unequal attraction for the shared electrons. Example: H₂O

Ionic Compound

Composed of positive and negative ions combined so that the number of positive and negative charges is equal.

Ionic bonds are bonds with two different types of elements, from different groups, and contain ions, making them conductors. Covalent bonds are bonds with two different types of elements, from the same group, and do not contain ions, making them insulators.

Malleability

The ability of a substance to be hammered or beaten into a thin layer.

Ductility

The ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire.

Electron-Dot Configuration

A notation in which only the number of valence electrons is shown around the element’s symbol.

Types of Covalent Bonds

Single Covalent Bond

A covalent bond formed by sharing one electron pair between two atoms.

Double Covalent Bond

A covalent bond formed by sharing two electron pairs.

Triple Covalent Bond

A covalent bond formed by sharing three electron pairs.

Octet Rule

A general rule of thumb that applies to most atoms.

Numerical Prefixes

• 1: mono-
• 2: di-
• 3: tri-
• 4: tetra-
• 5: penta-
• 6: hexa-
• 7: hepta-
• 8: octa-
• 9: nona-
• 10: deca-