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Periodic Table Atoms
PT and counting atoms
Question | Answer |
---|---|
atom | The smallest particle into which an element can be divided and still have the properties of that element. |
proton | A positively – charged particle that is located in the nucleus of an atom. |
neutron | A particle with no charge that is located in the nucleus of the atom. |
electron | A negatively – charged particle that is located outside of the nucleus of the atom. |
nucleus | The center of an atom, containing the protons and neutrons. |
electron cloud | The region inside an atom where electrons may be found. |
valence electrons | The electrons in the outermost energy level of an atom. |
atomic number | The number of protons in the nucleus of an atom. |
atomic mass | The average mass of one atom of an element. |
compound | A substance made of two or more elements that are chemically combined. |
Periodic Table of Elements | A chart where all of the elements are arranged according to their atomic number and properties. |
group/families | A vertical column of elements on the periodic table. Shows number of valence electrons. |
period | A horizontal row of elements on the periodic table. Shows number of shells/energy levels. |
physical property | A property of a substance that can be observed without changing the identity of the matter. |
chemical property | A property of a substance that is based on its ability to react with another substance. |
metal | An element that is shiny, ductile, malleable, and a good conductor. |
nonmetal | An element that is not shiny, ductile or malleable and is not a good conductor. |
metalloid | An element that has properties of both metals and nonmetals. |
chemical reaction | A change that takes place when two or more substances interact to form new substances. |
chemical formula | A description that uses numbers and element symbols to represent the atoms that make up a compound. |
reactant | A starting material in a chemical reaction. |
product | A substance formed from a chemical reaction. |
matter | Anything that has mass and takes up space. |
molecule | Two or more bonded atoms. |
subscript | The total number of atoms of an element in a chemical formula. |
coefficient | The total number of molecules of a chemical formula. |