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8th Unit 7b
Nature of Matter Key Terms part 2
Term | Definition |
---|---|
Atom | The smallest particle of an element that can exist either alone or in combination |
Element | A substance which cannot be separated into smaller parts and still retain its chemical identity. For example, sodium (Na) is an element. |
Kinetic Energy | Energy due to motion of a mass |
Law of Conservation of Energy | Basic law of nature which claims that energy is neither created nor destroyed but rather changes form |
Mass | The measurement of the amount of matter that an object contains |
Metal | A substance that is a good conductor of electricity and heat. They also have the properties of being ductile, malleable and shiny |
Metalloid | A substance that has some properties of metals and some properties of nonmetals |
Mixtures | A material made up by two or more different substances which are mixed but are not combined chemically |
Nonmetal | A substance that lacks the properties of a metal which are brittle and are poor conductors of heat and electricity |
Potential Energy | A form of energy that can be converted to other, more useful forms; stored energy |
Radioactive | A property of an element that causes it to spontaneously decay into other smaller elements |
Weight | The mathematical relationship between mass and gravitational pull; Mass x Gravity |
Ductile | Capable of being drawn out into wire or thread |
Malleable | Capable of being extended or shaped by beating with a hammer or by the pressure of rollers |
Conductor | A material or object that allows electricity or heat to move through it |
Period | A row on the Periodic Table. Every element in the row has the same number of atomic orbitals or energy levels. |
Group | A column of the Periodic Table. The elements in each column have the same number valence electrons. |
Valence electrons | The number of electrons in the outer orbital. |
Halogens | A family of elements all of which have 7 valence electrons and are found in group 17 on the Periodic Table. |
Noble Gases | A family of inert elements all of which have 8 valence electrons and are found in Group 18 (sometimes called Group 0) on the Periodic Table. |
Alkaline Metals | A family of elements all of which have 1 valence electrons and are found in group 1 on the Periodic Table. |
Alkaline Earth Metals | A family of elements all of which have 2 valence electrons and are found in group 2 on the Periodic Table. |