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Elements: substances that can’t be discomposed into simpler substances.
Atom: unit of which elements are made of.
Proton: a positively charged particle. (Found in nucleus)
Electron: a negativelycharged particle. (Found in orbits)
Neutron: a particle that has no charge. (Found in nucleus)
Compound: substance that is composed of the atoms of two or more elements and always contains the samerelative masses.
Chemical Formula: presentation of a molecule in which the symbols for the elements are used to indicate the types of atoms present and subscripts are used to show relative number ofatoms for alkanes. Example: H2O
Nuclear Atom: an atom with dense center of positive charge.
Isotopes: atoms with the same number of protons but different number of neutrons.
Atomic Number: numberof protons in a nucleus.
Mass Number: the sum of neutrons and protons in a nucleus.
To find mass number you do: A= Z+ number of electrons
Groups: families of elements with similar chemicalproperties that lie in the same vertical columns on the periodic table.
1. Alkali metals: first column of elements, group 1. (3, 11, 19, 37, 55, 87.)
2. Alkaline Earth Metals: second column ofelements, group 2. (4, 12, 20, 38, 56, 88.)
3. Halogens: group 7. (9 17, 35, 53, 85.)
4. Noble Gases: group 8. (2, 10, 18, 36, 54, 86, 118.)
5. Transition Metals: several series ofelements in which inner orbits (D and F) are filled. (21-30, 39-48, 57, 72-80, 89, 104-112.)
6. Non metals: elements that have no metal.
7. Lanthanides: the lanthanides comprise elements 57 to 71.8. Actinides: the actinides comprise elements 90 to 103.

Non metals

Characteristics of metals:
* Conduction of heat and electricity.
* Malleability.
* Ductility.
* Shinyappearance.
Metalloids: elements that have both, metal properties and non metal properties.
Ion: charged entity.
Cation: positive ion.
Anion: negative ion.
Binary compound: compound composed of...