The average mass of atoms of an element, calculated using the abundance of isotopes in a naturally-occurring element, indicates the "size" of an atom.

Smallest part of an element that is still the same substance, constructed of negatively charged electrons orbiting a positively charged nucleus

Positively charged "center", containing protons and neutrons

Positive charge, found in nucleus, responsible for the identity of an element

Neutral charge, found inside nucleus, has the most mass of all the subatomic particles

Negative charge, found in "electron cloud" outside nucleus, has the least amount of mass of all the subatomic particles

The number of electrons present in the outer ring or energy level in an atom

Fixed paths or orbits that surround the nucleus where electrons are found (2 electrons on 1st, 8 electrons on 2nd, 18 electrons on 3rd)

Chemical elements in order of increasing atomic number

Substance whose atoms all have the same number of protons, the simplest substance that cannot be broken down any further by chemical means

A horizontal row on the periodic table,

Vertical column on the periodic table

Equal to the number of valence electrons

These elements typically form cations, elements are typically good conductors and are malleable, found on the left side of the periodic table

Typically form anions, poor conductors, break apart easily in the solid state, found on right side of the periodic table

Semiconductors of heat/electricity, can have characteristics of both metals and nonmetals

The ability of an atom, molecule, or compound to undergo a chemical reaction

The point at which a substance enters the gas phase

The point at which a substance enters the liquid phase

The ability of a substance to be bent, shaped, or formed

The ability to conduct electricity

Atom changes mass due to change in neutron count

The charge of an atom changes as electrons are gained or lost

A negatively charged ion, electrons gained

A positively charged ion, electrons lost

A physical property that causes matter to experience a force within an electromagnetic field

A characteristic of matter that changes the appearance of matter but not its composition.

Parts of an atom: protons, neutrons and electrons

Smallest particle in a chemical element or compound that has the chemical properties of that element or compound; made up of atoms that are held together by chemical bonds

A characteristic of a substance that is observed during a reaction in which the composition of the substance is changed

Expressed as a positive or negative number indicating the ionic charge of the element or ion

A measure of the tendency of an atom to attract a bonding pair of electrons

The forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions )

Any of the elements found in Group 1 of the periodic table, the first column

Six elements in group 2 of the periodic table

Five elements from group 17 missing an electron from their outermost shell, they react readily with most metals to form salts

Elements located in groups 3 through 12 of the periodic table

A group of rare gases, that exhibit great stability and extremely low reaction rates found in group 18 on the periodic table