Chemistry
ductile
able to be drawn into thin wires
malleable
able to be hammered into different shapes
state of matter
any of the four physical forms of matter
matter
anything that has mass and takes up space
nucleus
center, or core, of an atom (where the protons and neutrons are located)
condensation
change from a gas to a liquid
evaporation
change from a liquid to a gas at the surface of the liquid
freezing
change from a liquid to a solid
sublimation
change from a solid directly to a gas
melting
change from a solid to a liquid
physical change
change that does not produce new substances - melting an ice cube or ripping paper. You can get the ice back and the paper is still paper.
chemical change:
change that produces new substances - burning wood to make ashes or mixing mentos and coke. You can't get the wood or the mentos back.
properties
characteristics used to describe an object
metal
element that has the property of shiny luster, ductility, and malleability
nonmetal
element that lacks most of the properties of a metal, is not shiny, does not conduct electricity or heat well, is not malleable so it is called brittle or breakable.
halogens
elements that make up Group 17 in the periodic table
noble gases
elements that make up Group 18 in the periodic table
chemical bond
force of attraction that holds atoms together
atomic number
number of protons in the nucleus of an atom. This is the same number as the number of electrons
coefficient
number that shows how many molecules of a substance are involved in a chemical reaction
subscript
number written to the lower right of a chemical symbol in a chemical formula
electron
particle that has a negative charge - located in rings outside the nucleus of an atom. You can figure out the number of electrons by looking at the atomic number of an element.
proton
particle that has a positive charge - located in the nucleus of an atom. You can figure out the number of protons by looking at the atomic number of an element.
neutron
particle that has no charge - located in the nucleus of an atom. You can figure out the number of neutrons by SUBTRACTING the atomic Mass minus the atomic number.
energy level
place in an electron cloud where an electron is most likely to be found - rings. Remember, 2-8-18-32.
chemical reaction
process in which new substances with new chemical and physical properties are formed
molecule
smallest part of a substance that has all the properties of that substance - more than one element, like hydrogen and oxygen make water
atom
smallest part of an element that can be identified as that element
plasma
state of matter made up of electrically charged particles - needs high temperatures and high pressure
gas
state of matter that has no definite shape or volume
solid
state of matter with a definite shape and volume
liquid
state of matter with a definite volume but no definite shape
chemical equation
statement in which chemical formulas are used to describe a chemical reaction
element
substance that CANNOT be chemically broken down into simpler substances
reactant
substance that is changed in a chemical reaction
product
substance that is formed in a chemical reaction
luster
the way a material reflects light
atomic mass
total mass of the protons and neutrons in an atom
chemical formula
way of writing the name of a compound using chemical symbols
