Fundamentals of Atomic Structure and Bonding

Density

Relationship between the mass of the substance and how much space it takes up (volume)

Atomic Number

# of protons

Mass Number Determinants

Protons + neutrons

Neutral Atom

Atom with no charge.

Ion

An atom that gained or lost one or more electrons.

Isotope

Atoms with the same # of protons but different # of neutrons

Mass Number

The total # of protons + neutrons.

Atomic Weight

The weighted average of the masses of all naturally occurring isotopes.

Thomson's Model

Plum pudding model. Electrons swimming in a "sea" of positively charged matter.

Thomson's Discovery

Electrons.

Rutherford's Experiment

Thin gold foil, a source of alpha particles, and a fluorescent screen to detect particle deflections as they passed through the foil.

Rutherford's Experiment Result

Atoms have a tiny, dense, positively charged nucleus, as most alpha particles passed through, but some were deflected.

Bohr's Model

Electrons orbit the nucleus in fixed paths with specific energy levels. Electrons can jump between these levels by absorbing or emitting energy.

Avogadro's Number

6.022 x 10^23

Photoelectric Effect

When light shines on a metal, electrons can be ejected from the surface of the metal.

Excited State of Electron

Absorbs energy, jumps an energy level.

Flame Test Colors

Correspond to specific frequency/energy level jumped.

Wavelength

Distance between two consecutive peaks or troughs of a wave. It tells us how long one wave is.

Frequency

Number of waves that pass a point in one second. It tells us how fast the waves are moving.

Wavelength and Frequency Relationship

Inverse.

Energy and Frequency Relationship

Direct.

Electronegativity

Ability to gain an electron.

Atomic Radius

Distance from the nucleus of an atom to the outermost electron. It measures the size of an atom.

Group 1

Alkali metals.

Group 2

Alkaline metals.

Group 3-12

Transition metals.

Group 17

Halogens.

Group 18

Noble gases.

Cation

Positively charged ions. When an ion loses 1 or more electron(s).

Anion

Negatively charged ions. When an ion gains 1 or more electron(s).

Bond Formation

To complete outer shell.

Octet Rule

Atoms prefer to have 8 electrons on the outer shell.

Conductivity of Ionic Compounds

When dissolved in water or melted, they conduct electricity because the ions are free to move.

Conductivity of Metallic Compounds

Conduct electricity well in both solid and liquid forms.

Conductivity of Covalent Molecules

Do not conduct electricity in solid or liquid form.

Nonpolar

No dipole.

Polar

Dipole.