Question | Answer |
atom | is the smallest piece of an element that still represents that element.
Atoms of different elements are different sizes. |
electron | is a particle with one negative charge. |
nucleus | most of an atom's mass and positive charge is concentrated in a small area in the center of the atom. |
proton | is an atomic particle that has one positive charge. |
neutron | is a neutral particle that exists in the nucleus 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. |
neutron atom | the number of electrons equals the number of protons |
Isotopes | are atoms of the same element that have different numbers of neutrons. |
mass number | is the sum of the number of protons and neutrons in an atom.Mass number= # of protons + # of neutrons. |
average atomic mass | is 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. |
metal | 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. |
non-metal | poor conductors of thermal energy and electricity, most are gases at room temperature: solid forms tends to be brittle. |
chemical bonds | is a force that holds two or more atoms together. |
valence electron | is an outermost electron of an atom that participates in chemical bonding. Valence electrons have the most energy of all electrons in an atom. These outermost electrons are the only electrons involved in chemical bonding. |
electron dot diagram | a model that represents valence electrons in an atom as dots around the element's chemical symbol. |
Covalent Bond | is a chemical bond formed when two atoms share one or more pairs of valence electrons. The atoms then form a stable covalent compound. |
molecule | is a group of atoms held together by covalent bonding that acts as an independent unit. |
chemical formula | is a group of chemical symbols and numbers that represent the elements and the number of atoms of each element that make up a compound. |
ion | an atom that is no longer electrically neutral because it has lost or gained valence electrons. |
ionic bond | the attraction between positively and negatively charged ions in an ionic compound. |
Metallic Bonds | is a bond formed when many metal atom share their pooled valence electrons. |