SCIENCE 8th grade TEST: STRUCTURE OF MATTER
pure substance
A substance with a definite composition and set of chemical and physical properties.
Subscript
A number in a chemical formula that tells the number of atoms of each element that are in the molecule
Coefficient
A number in front of a chemical formula in an equation that indicates how many molecules are involved
Matter
Anything that has mass and takes up space (volume)
Atom
The smallest particle of an element and the basic unit of matter (it is made up of the subatomic particles protons, electrons, and neutrons)
Names and formulas reveal __________
chemical composition
Amorphous
describes solids with no pattern or order
Neutrons
has no charge, located in the nucleus of the atom
Nucleus has majority of the atom's ___________
mass
Electrons
negatively charged particles located in the electron cloud of the atom, moves at nearly the speed of light
Protons
positively charged particles, known as the atomic number, and determines the element
Molecule
smallest unit of a chemical compound, formed when two or atoms join together
Atomic mass
the average mass of all the protons and neutrons in a mass (the average atomic mass= Protons + neutrons amu)
Element
the basic form of matter which cannot be broken down any further, a pure substance made up of many atoms with the same atomic number
Compounds
two or more different atoms bonded together, the molecules of pure substances
The electron cloud has majority of the atom's __________
volume
Crystalline lattice
what causes crystals to form in their neat and order structure