click below
click below
Normal Size Small Size show me how
a&pt
unit 3 lesson 1&2
Term | Definition |
---|---|
atom | the smallest particle into which an element can be divided and still be the same element |
electrons | negatively charged particles |
nucleus | a small dense center that has a positive charge and is surrounded by moving electrons |
protons | the positively charged particles in the nucleus |
neutrons | uncharged particles in the nucleus |
electron cloud | the area around the nucleus in which electrons move |
mass number | the total number of protons and neutrons in an atom's nucleus |
periodic table | Menedeleev's arrangement of the elements |
chemical symbol | an abbreviation for the element's name |
average atomic mass | the weighted average of the masses of all the naturally occurring isotopes of that element |
metals | elements that are shiny and conduct heat and electricity well |
nonmetals | poor conductors of heat and electricity |
metalloids | elements that have some properties or metals and some properties or nonmetals |
group | the vertical column of elements |
period | horizontal row of elements |
atomic number | the number of protons in an atom's nucleus |