The Nature of Matter

Vocabulary flashcards covering the nature of matter, subatomic particles, atomic properties, and chemical compounds.

Chemical Element

A pure substance that consists entirely of one type of atom, represented by a one- or two-letter symbol.

CHNOPS

An acronym representing the most common elements in living things: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, and Sulfur.

Atomic Number

The number of protons in an atom, which also equals the number of electrons.

Atomic Mass

The total sum of protons and neutrons in an atom ($\text{Atomic Mass} = \text{Protons} + \text{Neutrons}$).

Proton

A positively charged subatomic particle ($+$\text{ charge}) located at the center of the atom.

Neutron

A subatomic particle carrying no charge at all located in the nucleus; calculated as: $\text{Neutrons} = \text{Mass} - \text{Atomic number}$.

Nucleus

The structure at the center of the atom formed together by protons and neutrons.

Electron

A negatively charged subatomic particle ($-$\text{ charge}) that surrounds the nucleus in energy levels.

Energy Levels

Regions surrounding the nucleus where electrons reside; the 1st level holds $2$ electrons, the 2nd level holds $8$ electrons, and the 3rd level holds $18$ electrons.

Chemical Compound

A substance formed by the chemical combination of two or more elements in definite proportions.