Chapter 2 Vocabulary
• Matter - Anything that takes up space and has mass.
• Element - Any substance that cannot be broken down to any other substance by
chemical reactions.
• Compound - A substance consisting of two or more different elements
combined in a fixed ratio.
• Essential Elements - A chemical element required for an organism to survive,
grow, and reproduce.
• Trace Elements - An element indispensable for life but required in extremely
minute amounts.
• Atom - The smallest unit of matter that retains the properties of an element.
• Neutrons - A subatomic particle having no electrical charge (electrically neutral),
with a mass of about 1.7 x 10-24 g, found in the nucleus of an atom.
• Protons - A subatomic particle with a single positive electrical charge, with a
mass of about 1.7 x 10-24 g, found in the nucleus of an atom.
• Electrons - A subatomic particle with a single negative electrical charge and a
mass about 1/2,000 that of a neutron or proton. One or more electrons move
around the nucleus of an atom.
• Atomic Nucleus - An atom's dense central core, containing protons and
neutrons.
• Dalton - A measure of mass for atoms and subatomic particles; the same as the
atomic mass unit, or amu.
• Atomic Number - The number of protons in the nucleus of an atom, unique for
each element and designated by a subscript.
• Mass Number - The total number of protons and neutrons in an atom's nucleus.
• Matter - Anything that takes up space and has mass.
• Element - Any substance that cannot be broken down to any other substance by
chemical reactions.
• Compound - A substance consisting of two or more different elements
combined in a fixed ratio.
• Essential Elements - A chemical element required for an organism to survive,
grow, and reproduce.
• Trace Elements - An element indispensable for life but required in extremely
minute amounts.
• Atom - The smallest unit of matter that retains the properties of an element.
• Neutrons - A subatomic particle having no electrical charge (electrically neutral),
with a mass of about 1.7 x 10-24 g, found in the nucleus of an atom.
• Protons - A subatomic particle with a single positive electrical charge, with a
mass of about 1.7 x 10-24 g, found in the nucleus of an atom.
• Electrons - A subatomic particle with a single negative electrical charge and a
mass about 1/2,000 that of a neutron or proton. One or more electrons move
around the nucleus of an atom.
• Atomic Nucleus - An atom's dense central core, containing protons and
neutrons.
• Dalton - A measure of mass for atoms and subatomic particles; the same as the
atomic mass unit, or amu.
• Atomic Number - The number of protons in the nucleus of an atom, unique for
each element and designated by a subscript.
• Mass Number - The total number of protons and neutrons in an atom's nucleus.
