Definition
Vocabulary Word
CHAPTER 7
Atom the smallest piece of any element
Electron a negatively charged particle that orbits the nucleus of an atom
Nucleus
the central part of an atom that contains most of the mass; contains two
types of particles: positively charged protons and uncharged neutrons
Protons a positively charged particle found in the nucleus of an atom
Neutrons a particle found in the nucleus of an atom; it has no charge
Subatomic particles
one of the parts that make up the atom; includes electrons,
protons, and neutrons
the pattern of light that an element gives off when its atoms absorb electrical
Emission spectrum or heat energy and re-emit that energy as light; each element will give off a
very specific combination of wavelengths, or colours, of light
Shells a specific “allowed” orbit in which electrons circle the nucleus
Atomic number
the number of protons in the nucleus of an atom; used to identify
the element
the total number of protons and neutrons in the nucleus of
an atom
a charged atom; results when electrons are added to or removed from
Ion
an atom
Mass number
Negative ion
Positive ion
an atom that has more electrons than protons; the ion has a
negative charge
an atom that has fewer electrons than protons; the atom has a
positive charge
Ion charge the charge of an ion; can be positive or negative
Atomic mass
the average mass of all of the naturally occurring isotopes of an
element
a diagram used to help us to visualize the arrangement of electrons in an
Bohr diagram atom; drawn as a series of concentric rings (the shells) around a nucleus with
electrons as dots on the rings
Ionic compound
a compound that forms when metal atoms react with
non-metal atoms
the process of transferring electrons between metals and non-metals
Electron transfer to create an ionic bond; can occur in a collision between metal and
non-metal atoms
Ionic bond
the bond between metal and non-metal ions; based on electrical
attraction between positive and negative ions
two or more atoms joined together by chemical bonds; the smallest particle of
Molecules a pure substance that still has the properties of the pure substance; for
example, a water molecule