Download Atom Building blocks of matter Proton Sub

Atoms and The Periodic Table Vocabulary
Atom
Building blocks of matter
Proton
Sub-atomic particle with positive (+) charge;
located in nucleus of atom; determines identity of
element
Neutron
Sub-atomic particle with no charge, located in the
nucleus of the atom
Electron
Sub-atomic particle with negative charge; much
smaller than protons and neutrons
Nucleus
Center of atom; made of protons and neutrons
Valence Electron
Electron found in outermost shell of an atom;
determines atoms chemical properties
Atomic Number
Number of protons in the nucleus of an atom
Mass number
Protons + neutrons
Atomic Mass
Weighted average of masses of isotopes of
each atom
Isotope
Atom with same # of protons as other atoms of
that element, but different # of neutrons
Ion
An atom that has gained or lost one or more
electrons; thus having a + or - charge
Bohr Model
Model used to visualize atomic structure
Lewis Dot Structure
Used to show number of valence electrons in
an atom
pH scale
Scale used to show acidity or alkalinity of
something.
Acid
Compound which increases H+ ions when
dissolved in H2O
Base
Compound which increases hydroxide ions (OH-)
when dissolved in H2O
Gravitational Force
Attraction of objects due to their masses and
distance; weakest force
Electromagnetic
Force
Like charges repel and opposite charges attract;
Holds electrons around the nucleus
Weak Nuclear Force
Force responsible for radioactive decay.
Strong Nuclear Force
Holds the atomic nucleus together; Counteracts
the electromagnetic force
Periodic Table
Table where elements are arranged by
increasing atomic number
Group
Vertical (up and down) column of periodic
table; elements in group share chemical
properties (same # valence electrons)
Period
Horizontal row of elements in periodic table; =
how many orbitals atoms have
Metals
Good conductors of heat and electricity; to left
of stair step
Non-metals
usually gases or brittle solids at room temp; are
poor conductors; to right of stair step
Metalloids
Have characteristics of metals and non-metals;
make up stair step