Chem - Atomic Structure

Atom

1. The smallest particles of matter, that we cannot break down further by chemical means.
2. Consists of a nucleus and electrons that orbit around it whose mass is measured in atomic mass units. protons have a 1+ positive charge while electrons have a 1- negative charge.
3. Every atom has an equal number of protons and electrons.

Element

Substances that cant be split into anything simpler by chemical means. An element contains only one kind of atom

Molecule

Consists of two or more atoms chemically bonded.

Proton/Atomic Number

The number of protons in an atom. You can identify an atom by the amount of protons because every atom has a different number.

Nucleon/Mass Number

The total number of protons and neutrons in an atom is called its nucleon number. Protons and neutons form the nucleus so called nucleons. Mass Number = number of protons + number of neutrons

Isotopes

1. Atoms of the same element with different numbers of neutrons.

   2. have the same chemical properties because they have the same number of protons and electrons and therefore the same electronic configuration.

Relative Atomic Mass

Average mass of an atom, taking account each isotope present in a naturally occurring sample of an element. calculate w relative abundances and mass number
(% of isotope A x mass of isotope A) + (% of isotope B x mass of isotope B)/100