Chapter 2: The Chemistry of Life >

Atom

a basic unit of matter

Nucleus

the central core of an atom

Electron

a negatively charged particle surrounding the nucleus

Element

a pure substance; made of only one type of atom

Isotope

a form of an element consisting of the same protons, but varying neutrons; different atomic mass

Compound

one type of molecule made up of more than one element

Ionic bond

a chemical bond formed from the exchange of electrons

Ion

an atom with a positive or negative charge

Covalent bond

a kind of bond between atoms formed from shared electrons

Molecule

two or more atoms joined together; the smallest particle of a substance

Van der Waals forces

A weak attraction between molecules that is dependent on distance, geckos use this to temporarily stick on walls.

Mass number

Protons and neutrons added

Atomic mass

the weighted average of the isotopes of an element

Atomic number

the number of protons in an atom

Weak Interactions

weak forces which create a slight attraction between molecules when they are close together

Radioactive Isotopes

The nuclei of the isotope are unstable, so they will break down at a constant rate over time.

Max number of electrons in a valence shell

eight

What kind of bond does this diagram contain?

Covalent bond

Trace element

A chemical element present in a minuscule quantity

6 most common elements in living things?

carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus

99% of the human mass's elements are...

oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus

AMU

Atomic Mass Unit