Definitions

Chemical bond

An electrostatic force of attraction that holds two or more atoms, ions, or molecules together.

Electrostatic force

The force of attraction involving oppositely charged particles.

Ionic bond

The strong forces of attraction between oppositely charged ions.

Covalent bond

The strong electrostatic forces of attraction between the shared pair of electrons and the positively charged nuclei of both atoms.

Acid

A substance that forms hydrogen ions (H+) when dissolved in water.

Alkali

A substance that forms hydroxide ions (OH-) when dissolved in water.

Thermal decomposition

The process in which compounds break down into two or more substances with the effect of heat.

Electrolysis

The process in which compounds break down into two or more simpler substances with the effect of electricity.

Oxidation

The process in which a substance gains oxygen.

Reduction

The process in which a substance loses oxygen.

Law of conservation of mass

The law stating that mass is not gained or lost in a chemical reaction, hence, the total mass of products must equal the total mass of reactants.

Contact force

Forces that act when two interacting objects have physical contact with each other.

Non-contact force

Forces that act over a distance without physical contact between two interacting objects.

Frictional force

The contact force that acts between two surfaces/objects in contact that tends to oppose or resist motion.

Inertia

The resistance of a body to change its state of rest or motion.

Pressure

The amount of force acting perpendicularly on a unit area.

Principle of moments

States that for an object to be in rotational equilibrium, the sum of clockwise moments about any pivot is equal to the sum of anticlockwise moments about the same pivot.

Stability

The ability of an object to return to its original position after being tilted slightly.

Stable equilibrium

Occurs when the center of gravity rises and then falls back again.

Unstable equilibrium

Occurs when the center of gravity falls and continues falling.

Neutral equilibrium

Occurs when the center of gravity neither rises nor falls; it remains at the same level.