Basic Chemistry Vocabulary
Standard Biology
Zito/Farrell
SY 2009-2010
Atom
• the smallest component of an element
having the chemical properties of the
element
• made up of a specific arrangement of
protons, neutrons, and electrons
Nucleus
• positively charged, dense center of an
atom
• contains the protons and the neutrons
Proton
• a particle of an atom with a positive charge
of +1 and a mass of 1 unit
• always found in the nucleus of the atom
• An atom of a specific element ALWAYS
has the same number of protons.
• If you change the number of protons, you
make a DIFFERENT element.
Neutron
• a particle of an atom with a neutral charge
(charge of 0) and a mass of 1 unit
• always found in the nucleus of the atom
• An atom can have different numbers of
neutrons.
• If you change the number of neutrons, you
make a heavier or lighter ISOTOPE of the
SAME element.
Electron
• a particle of an atom with a negative
charge of -1 and a mass of 0 units
• always outside of the nucleus of the atom
• Electrons live in layers called clouds or
orbitals.
• An atom of an element can have different
numbers of electrons.
• (more on the next slide)
Electrons – ion formation
• Atoms with the SAME number of protons
and electrons are called stable atoms, or
just plain old atoms.
• An atom that loses or gains electrons is
called an ION.
• Losing electrons makes a positive ion
(cation)
• Gaining electrons makes a negative ion
(anion)
Molecule
• One or more atoms bonded together
• Each molecule that exists has a certain
number of atoms, bonded together in a
specific arrangement
Molecule Examples
• Oxygen is O2 and
• looks like this.
• Ex: Glucose is always
• C6H12O6 and looks
• like this:
Compound
• Some molecules are compounds, some
are not.
• A compound has at least two kinds of
atoms.
• Sugar has C, H, & O. it is a compound.
• Oxygen only has O atoms. It’s not a
compound. (But it is still a molecule.)
Bonds Between atoms 1
• Electrons are the part of the atom involved
in bonding.
• Sometimes one atom totally gives up an
electron and another one takes it. This is
Ionic Bonding (because ions are made).
Bonds Between atoms 2
• Electrons are the part of the atom involved
in bonding.
• Sometimes two atoms share an electron.
This makes a COVALENT bond (because
they are CO-operating).
Physical Changes
• anything that does not change the
chemical structure of the molecules
(basically, anything that makes it get
bigger, get smaller, or change shape)
• Freezing, melting, evaporating,
condensing, crushing, stacking,
increasing, dissolving…
Chemical Changes
• anything that changes what you have into
something else
(difficult or impossible to reverse)
• Ex: Burning paper
(C6H12O6)n + O2 = C + H2O = CO2
Paper + Oxygen turn into Water, Carbon
Dioxide, and Carbon dust.
Mixture
• two or more substances mixed together
- not in fixed proportions
- not chemically bonded together
- can be separated
*Blood is a mixture.
Solution
• a homogeneous (evenly combined)
mixture of two or more substances
*frequently (but not necessarily) a liquid
• Ex: sugar water
• Solute – the part that
dissolves (sugar)
• Solvent – The part that
it dissolves into (water)