Download Structure of Matter Vocab Structure of Matter vocab

Structure
of
Matter Unit
Vocabulary
Atomic number
The number of protons in an
atom’s nucleus
Chemical symbol
A shorthand way to write the
name of an element.
Example: Ag = Gold
Electron
Negatively charged particles that
move around the nucleus of an
atom.
Isotope
Atoms of the same element that
have different numbers of
neutrons
Example: Boron – 10 and Boron 11
Neutron
Atomic particle with no charge,
neutral, that is part of an atoms
nucleus
Mass number
Sum of the numbers of the protons
and neutrons in an atom’s nucleus
Periodic table
A chart of elements arranged
according to repeated changes in
properties
Proton
Atomic particle with a positive
charge that is part of an atom’s
nucleus
Quark
6 small particles that make up a
neutron and proton
Boiling point
The temperature at which vapor
bubbles from in a liquid form to
rise to the surface, increasing
evaporation
Density
Describes how tightly packed a
substance’s molecules are
Density formula
The mass per unit volume of a material
D=M/V
D=density M=mass V=volume
Ion
A positively or negatively charged
atom
Nonpolar molecule
A molecule that does not have
oppositely charged ends
Toxic
Hazardous substance that can
injure living tissues
Chemical formula
A precise statement that tells which
elements are in a compound and
their ratios
Chemically stable
Describes an atom whose outer
energy level is completely filled
with electrons
Corrosive
Hazardous compound that attacks
and alters metals, human tissue or
other materials
Covalent bond
A type of chemical bond formed by
atoms when they share electrons,
producing molecules
Chemical bond
The force that holds together the
atoms in a compound, occurs
because atoms of most elements
become more stable by gaining,
losing and sharing electrons