Chapter 2 Flashcards
Anion
A negatively charged ion
Atom
The smallest unit of matter that retains the properties of an element
Atomic Mass
The total mass of an atom, numerically equivalent to the mass in grams of 1 mole of the atom
Atomic Nucleus
An atom’s dense central core, containing protons and neutrons
Atomic Number
The number of protons in the nucleus of an atom, unique for each element and designated by a subscript
Cation
A positively charged ion
Chemical Bond
An attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shell
Compound
A substance consisting of two or more different elements combined in a fixed ratio
Dalton
A measure of mass for atoms and subatomic particles; the same as the atomic mass unit, or AMU
Double Bond
A double covalent bond; the sharing of two pairs of valence electrons by two atoms
Electron
A subatomic particle with a single negative electrical charge and a mass about 1/2,000 that of a neutron or proton. One or more electrons move around the nucleus of an atom
Electronegativity
The attraction of a given atom for the electrons of a covalent bond
Electron Shell
An energy level of electrons at a characteristic average distance from the nucleus of an atom
Element
Any substance that cannot be broken down to any other substance by chemical reactions.
Energy
the capacity to cause change, especially to do work (to move matter against an opposing force)
Essential Element
A chemical element required for an organism to survive, grow, and reproduce