3. Matter: What is Matter? (Words to know before
standards a-f)
3. Each of the more than 100 elements of matter has
distinct properties and a distinct atomic structure. All forms
of matter are composed of one or more of the elements.
As a basis for understanding this concept:

Matter: Something that has mass, occupies space and exists as a
solid, liquid, gas, or plasma.

Elements: A substance composed of atoms having an identical
number of protons in each nucleus. Elements cannot be reduced to
simpler substances by normal chemical means.

Volume: The amount of space occupied by a three-dimensional object
or region of space, expressed in cubic units.
www.gly.uga.edu/schroeder/ geol3010/volume.gif

Mass: A measure of how much matter is in an object.

Atomic Structure: How the protons, electrons and neutrons are
arranged in an atom.
www.arpansa.gov.au/ images/basics/He_atom2.gif
8th Grade Science Standards – 3a – 3f
1
3a. Students know the structure of the atom and know it is
composed of protons, neutrons, and electrons.

Atom: A unit of matter, the smallest unit of an element, having all the
characteristics of that element and consisting of a dense, central,
positively charged nucleus surrounded by a system of electrons
education.jlab.org/ qa/atom_model_02.gif

Protons: A positively charged particle inside a nucleus
education.jlab.org/ atomtour/proton.gif

Neutrons: A neutral particle found in the nucleus

Electrons: A negatively charged particle found around the nucleus
revolving in orbitals.
education.jlab.org/ atomtour/electron.gif

Orbital: The path of an object as it revolves around another object.
www.biologylessons.sdsu.edu/. ../lab2/orbital.gif
8th Grade Science Standards – 3a – 3f
2
3b. Students know that compounds are formed by
combining two or more different elements and that
compounds have properties that are different from their
constituent elements.

Compounds: A substance made of two or more elements chemically
combined.

Organic Compounds: Most compounds that contain carbon.

Inorganic Compounds: any compound that does not contain carbon

Ionic Bond: The attraction between two oppositely charged ions and
electrons are transferred.
www.uoguelph.ca/ ~sadura/minref/min16.html

Covalent Bond: A chemical bond formed when two atoms share
electrons.
http://www.cartage.org.lb/en/themes/Sciences/Chemistry/Inorganicchemistry/Informationb
onding/CovalentBond/CovalentBond.htm

Molecule: A combination between two or more atoms.
statesymbolsusa.org/
Texas/Buckyball_Molecule.html
8th Grade Science Standards – 3a – 3f
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3c. Students know atoms and molecules form solids by
building up repeating patterns, such as the crystal structure
of NaCl or long-chain polymers.

Solids: A state of matter that has a definite volume and definite shape.
http://www.aa.washington.edu/research/dawgstar/program/program.html

Crystal: An orderly, three-dimensional pattern of ions or atoms in a
solid.
www.mineralminers.com/ html/rkxlrgh.stm

Polymers: A large, complex, carbon based molecule built from smaller
molecules joined together.

Lattice: A regular and repeated arrangement of atoms in a solid.
8th Grade Science Standards – 3a – 3f
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http://www.avogadro.co.uk/structure/chemstruc/molecular/molecular.htm
3d. Students know the states of matter (solid, liquid, gas)
depend on molecular motion.

Liquid: A state of matter which has no definite shape but has a definite
volume.
http://en.wikipedia.org/wiki/Liquid

Gas: A state of matter which does not have a definite shape or volume.
http://volcanoes.usgs.gov/Products/Pglossary/VolcGas.html

Thermometer: An instrument to measure temperature.
http://www.moreaucatholic.org/support/images/
8th Grade Science Standards – 3a – 3f
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
Molecular Energy: the energy stored in molecules.
http://www.geog.ucsb.edu/~joel/g110_w05/lecture_notes/pressure/pressure.html

Melting Point: The temperature at which a solid change into liquid.
http://discover.edventures.com/functions/termlib.php?action=&termid=236&alpha=m&searchStrin
g=

Freezing Point: The temperature at which liquid change into solid.

Boiling Point: The temperature at which liquids start to change into a gas.
www.elmhurst.edu/.../ images2/163boiling.gif

Condensation: The temperature at which gas changes into liquid.

Evaporation: The process that occurs when vaporization takes place only
at the surface of a liquid.
8th Grade Science Standards – 3a – 3f
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3d. Students know that in solids the atoms are closely
locked in position and can only vibrate; in liquids the atoms
and molecules are more loosely connected and can collide
with and move past one another; and in gases the atoms
and molecules are free to move independently, colliding
frequently.

Structural Energy: the energy within a structure of an atom.
3e. Students know how to use the periodic table to identify
elements in simple compounds.

Periodic Table: A chart of the elements showing the repeating pattern of
their properties.
cougar.slvhs.slv.k12.ca.us/. ../secondsemass.html

Atomic Number: the number of protons in an atom.
education.jlab.org/
glossary/atomicnumber.html
8th Grade Science Standards – 3a – 3f
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