V
chemical formula
symbols that show the elements in a compound and the ratios of atoms
radioactivity
the spontaneous emission of radiation by an unstable atomic nucleus
atoms
the basic particle from which all elements are made
nucleus
the central core of an atom which contains all the protons and neutrons
beta radiation
a fast-moving electron which is given off as nuclear radiation
chemical symbol
a one or two-letter representation of an element
ductile
a term used to describe a material that can be pulled out into a long wire
malleable
a term used to describe material that can be hammered or rolled into flat sheets
electrons
a tiny negatively charged particle that moves around the outside of the nucleus of an atom
valence electrons
the electrons that are in the highest energy level of an atom and that are involved in chemical bonding
nonpolar bonds
a covalent bond where electrons are shared equally
polar bonds
a covalent bond in which electrons are shared unequally
isotopes
an atom with the same number of protons and a different number of neutrons from other atoms of the same element
polyatomic ions
an ion that is made of more than one atom
ionic bonds
the attraction between oppositely charged particles
ion
an atom or group of atoms that has become electrically charged
metalloids
an element that has both characteristics of both metals and nonmetals
alloy
a mixture of two or more elements, at least one of which is a metal
half-life
the time it takes for half of the atoms of the radioactive elements to decay
covalent bonds
a chemical bond formed when two atoms share electrons
radioactive decay
the process in which radioactive elements break down, releasing fast-moving particles and energy