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Ch. 7 and Ch. 8
Elements
Term | Definition |
---|---|
Atom | is the smallest piece of an element that still represents that element |
Electrons | is particle with one negative charge |
Proton | is an atomic particle that has one positive charge. |
Neutron | is a neutral particle that exists nucleus of atom |
Nucleus | most of an atoms mass and positive charge is concentrated in a small area in the center of an atom |
Electron Cloud | is an area around an atomic nucleus where an electron is most likely to be located. |
Atomic number | number of protons in an atom of an element. |
Isotopes | are atoms of the same element that have different numbers of neutrons. Most elements have several isotopes. |
Mass Number | s the sum of the number of protons and neutrons in an atom. Mass number= # of protons + # of neutrons. |
Average atomic mass | s the average mass of the element's isotopes, weighted according to the abundance of each isotope. |
Ion | is an atom that is no longer neutral because it has gained or lost electrons. |
Metals | often shiny, good conductors of electricity and thermal energy:easily pulled into wires and hammered into sheets. |
Matalloids | have properties in common with both metals and nonmetals often used as semiconductors in electronic devices. |
Nonmetals | poor conductors of thermal energy and electricity, most are gases at room temperature: solid forms tends to be brittle. |