Biology Chapter 2: The Chemical Context Of Life

Front 1

element

Back 1

a substance that cannot be broken down into other substances by chemical reaction

Front 2

compound

Back 2

a substance consisting of two or more different elements combines in a fixed ratio

Front 3

essential element

Back 3

a chemical element required for an organism to survive, grow, and reproduce

Front 4

trace element

Back 4

an element indispensable for life but required in extremely minute amounts

Front 5

atom

Back 5

the smallest unit of matter that retains the properties of that element

Front 6

neutrons

Back 6

a subatomic particle having no electrical charge (electrically neutral) with a mass of about 1.7x10^-24g. Found in the nucleus of an atom

Front 7

protons

Back 7

a subatomic particle with a single positive electrical charge, with a mass of about 1.7x10^-24g. found in the nucleus of an atom.

Front 8

electrons

Back 8

a subatomic particle with a single negative charge and a mass of about 1/2,000 that of a neutron or proton. One or more electrons move around the nucleus of an atom.

Front 9

atomic nucleus

Back 9

an atom's dense central core, containing protons and neutrons.

Front 10

dalton

Back 10

atomic mass unit
1.6605x10^-27g

Front 11

atomic number

Back 11

the number of protons in the nucleus of an atom unique for each element and designated by a subscript to the left of the elemental symbol