EXAM REVIEW

Radioactivity

The process where an unstable nucleus emits particles and energy.

Radioisotopes

Atoms with unstable nuclei that can change into different elements during decay.

Alpha Radiation (α)

Positively charged particles consisting of 2 protons and 2 neutrons; least penetrating, stopped by paper.

Beta Radiation (β)

Electrons emitted by a nucleus; more penetrating than alpha, stopped by aluminum.

Gamma Radiation (γ)

High-energy rays with no mass or charge; most penetrating, reduced by lead or concrete.

Half-Life

The time required for half a sample to decay.

Nuclear Fission

The process of splitting a nucleus into smaller parts.

Nuclear Fusion

The process of combining nuclei to form a larger nucleus; occurs in stars at high temperatures.

Solute

The substance that is dissolved in a solution.

Solvent

The medium that dissolves the solute.

Dissociation

The process where ionic compounds separate into ions in a solution.

Dispersion

The process where molecules spread throughout a solvent.

Ionization

The chemical change when molecules form ions in a solution.

Solubility

The maximum amount of solute that can be dissolved in a solvent at a specific temperature.

Saturated Solution

A solution that contains the maximum amount of solute possible at a given temperature.

Unsaturated Solution

A solution that contains less solute than the maximum possible at a given temperature.

Supersaturated Solution

A solution that contains more solute than normally possible; unstable.

Concentration

A measure of the amount of solute in a specific volume of solution, typically measured as Molarity.

Acid

A substance that produces hydronium ions (H₃O⁺) in solution, has a pH less than 7.

Base

A substance that produces hydroxide ions (OH⁻) in solution, has a pH greater than 7.

Neutralization Reaction

A chemical reaction between an acid and a base that produces water and salt.

Chemical Reaction

A process where reactants transform into products, conserving mass and requiring balanced equations.

Dalton's Atomic Theory

The theory stating that elements are composed of atoms that combine in fixed ratios.

Thomson's Model of the Atom

Proposed the 'plum pudding' model, discovered electrons using cathode rays.

Rutherford's Gold Foil Experiment

An experiment that discovered the dense, positive nucleus and concluded that atoms are mostly empty space.

Proton

A positively charged subatomic particle found in the nucleus.

Neutron

A neutral subatomic particle found in the nucleus.

Electron

A negatively charged subatomic particle located outside the nucleus.