Chemistry level 1 NCEA

Ion

An atom (monoatomic or polyatomic) That has lost or gained electrons in order to gain a full stable outer shell.

Element

A pure substance made of only one kind of atom

polyatomic ion

an ion made of two or more atoms

monoatomic ion

a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons

word equation

an equation in which the reactants and products in a chemical reaction are represented by words

chemical formula

A combination of chemical symbols and numbers to represent a substance

Reactant

A chemical substance that is present at the start of a chemical reaction

product

A substance produced in a chemical reaction

chemical equation

A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products

Atom

Smallest particle of an element

Proton

A subatomic particle that has a positive charge and that is found in the nucleus of an atom

Electron

A subatomic particle that has a negative charge and is found in the shells of an atom

Neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

Nucleus

Center of an atom

valence shell

outermost electron shell

valence electrons

The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.

shells (orbitals)

Where the electrons generally are; found at different distances from the nucleus

atomic mass

Number of protons and neutrons

atomic number

the number of protons in the nucleus of an atom, and the number of electrons located in the shells

Electron arrangement

organisation of electrons in an atom by increasing energy shells.

HCl

Hydrochloric acid

H2SO4

Sulfuric acid

HNO3

Nitric acid