Chemical Basis of Life

Composition of substances and how they change

Study of Matter

Study of living organisms

Anything that has mass and takes up space

All matter is composed of fundamental substances called...

(iron, copper, silver, gold, aluminum, carbon, hydrogen, and oxygen)

Chemical combinations of elements

Large amounts of elements that the body require & make up more than 95%, by weight, of the human body
(Oxygen, hydrogen, carbon, nitrogen, sulfur, and phosphate)

Small amounts of elements the body require.
Many are important parts of enzymes & proteins.
Ultra-trace elements may be vital in small amounts (arsenic, in large amts. can be toxic)

Composed of elements and are the smallest complete units of elements.
Atoms vary in size, weight, & interaction with other atoms.

Attraction of atoms that combine with like or unlike atoms

Nucleus (always positively charged because of protons)
Electrons (e^-) - move around nucleus; almost weightless
Protons (p⁺) - inside nucleus; equal to neutrons in weight
Neutrons (n⁰) - inside nucleus; equal to protons in weight

The number of PROTONS in the atoms of an element.
(p)

The weight of PROTONS and NEUTRONS
(p + n)
(Electrons are almost weightless)

SAME atomic NUMBER; DIFFERENT atomic MASS
(Example: O¹⁶, O¹⁷, O¹⁸)
unstable isotopes are radioactive; emit energy or atomic fragments

A particle made up of 2 or more atoms

A shorthand used to indicate the types of atoms & the numbers in a molecule.
(Example: H₂O - indicates 2 atoms of hydrogen and 1 atom of oxygen)