Chemistry and Water

Matter

Anything that takes up space and has mass.

Element

A substance that cannot be broken down by a chemical reaction.

Compound

A substance consisting of 2 or more elements combined in a fixed ratio.

Isotopes

Atoms of an element that have different numbers of neutrons and therefore different masses.

Radioactive isotope

An isotope whose nucleus decays spontaneously and gives off energy.

Covalent bonding

A type of bonding where a pair of electrons is shared between atoms.

Ionic bonds

Bonds formed when one atom donates electrons to another atom.

Chemical reaction

The making and breaking of chemical bonds, involving reactants and products.

Cohesion

The sticking together of water molecules due to hydrogen bonding.

Adhesion

The sticking together of water molecules to other substances.

Kinetic energy

Energy of motion, including the motion of atoms and molecules.

Temperature

The average kinetic energy of molecules in matter.

Specific heat

The amount of heat absorbed or lost by 1 g of a substance to change its temperature by 1°C.

pH

A measure of the concentration of hydroxide ions (OH-) and hydronium ions (H3O+) in a solution.

Buffers

Substances that resist changes in pH by maintaining the concentration of hydroxide and hydronium ions.

Acid precipitation

Rain with a pH lower than 5.6, resulting from environmental pollution.

Neutral pH

A pH of 7, which is the pH of pure water.

Hydrogen bond

A weak bond formed when a hydrogen atom covalently bonds to one atom but is attracted to another atom.

High heat of vaporization

The amount of heat a liquid must absorb to be converted to gas, significant in water due to hydrogen bonds.

Matter

Anything that takes up space and has mass.

Element

A substance that cannot be broken down by chemical reaction (e.g., copper).

Isotopes

Atoms of an element with different numbers of neutrons and different masses.

Covalent Bonding

A chemical bond where a pair of electrons is shared between atoms.

Ionic Bond

A chemical bond formed when one atom donates electrons to another atom.

Chemical Reaction

The process of making and breaking chemical bonds between reactants and products.

Specific Heat

The amount of heat required to change the temperature of 1 g of a substance by 1°C.

pH

A measure of the concentration of hydroxide ions (OH-) and hydronium ions (H3O+) in a solution.

Buffer

A substance that resists changes in pH concentrations.

Acid Precipitation

Rain with a pH less than 5.6, which can damage aquatic life and soil chemistry.