BackGeneral Chemistry: Atoms, Isotopes, and Chemical Bonding
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Terms in this set (21)
Matter is anything that takes up space and has mass.
An atom is the smallest unit of an element and the smallest unit of matter.
Protons are positively charged, neutrons have no charge, and electrons are negatively charged.
Protons and neutrons are in the nucleus, electrons orbit in the electron shell.
The atomic number is the number of protons in the nucleus of an atom.
The mass number is the total number of protons and neutrons in the nucleus.
Number of neutrons = mass number - atomic number.
Valence electrons are electrons in the outermost energy shell of an atom.
The octet rule states atoms are more stable when their valence shell is full, usually with 8 electrons.
Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
A radioactive isotope is an unstable isotope that breaks down and emits energy as rays or particles.
A chemical bond is an attractive force between atoms that holds them together to form molecules or compounds.
Intramolecular bonds occur within a molecule; intermolecular bonds occur between molecules.
A covalent bond is formed by the sharing of electrons between two atoms.
Nonpolar covalent bonds share electrons equally; polar covalent bonds share electrons unequally due to electronegativity differences.
Electronegativity is an atom's attraction for electrons, scaled from 0 to 4.
Noncovalent bonds are interactions between atoms without sharing electrons, often involving partial or full charges.
An ion is an atom or molecule with a net electrical charge due to gain or loss of electrons.
Anions are negatively charged ions (gain electrons); cations are positively charged ions (lose electrons).
An ionic bond is an electrical attraction between oppositely charged ions.
A hydrogen bond is an interaction between a hydrogen atom bonded to a highly electronegative atom (F, O, or N) and another electronegative atom.