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Chemistry
Term | Definition |
---|---|
Element | made of one kind of atom. It can't be broken down during a chemical reaction. It combines with other elements to form compounds. |
Atomic number | located above the symbol Tells the number of protons in the nucleus of an atom. |
Period | elements in a horizontal line on the periodic table. These elements all have the same number of electron levels |
Mass number | number of protons and neutrons in the nucleus of an atom. It is the atomic mass rounded to the nearest whole number |
Atomic mass | decimal number below the symbol. It is the mass of the protons and neutrons in an element |
Atomic number | located above the symbol Tells the number of protons in the nucleus of an atom. |
Neutrons | take the atomic mass, and round to the nearest whole number . This gives you the mass number. Take the mass number and subtract the atomic number. |
Semimetals | have some properties of both metals and nonmetals.Some semimetals are shiny but cannot be shaped. |
Noble Gases | elements that do not combine easily with other elements. |
Nonmetals | most have the properties opposite of metals. Nonmetals are dull and cannot be shaped. |