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Chem Exam 3rd 9wks
Question | Answer |
---|---|
Nucleur charge | the positive charge on the nucleus |
electron shielding | results from inner electronsthat reduce the pull of the nucleus on outer electrons |
atomic radii | half the distance between the nuclei of identical atoms that are bonded together |
ions | an atom or group of bonded atoms that has a positive or negative charge |
anion | a negative ion |
cation | positive ion |
ionization | any process that results in the formation of ions |
ionization energy | the energy required to remove an electron from an electron from a neutral atom of an element |
electron affinity | the energy change that occurs as an electron is added to a neutral atom |
electronegativity | a measure of the ability of an atom in a chemical compound to attract electrons |
valence electrons | the electrons to be lost, gained, or shared in the formation of chemical compounds |
chemical bond | a mutual electrical attraction between the nuclei and valence electrons of different atoms tat binds the atoms together |
ionic bonding | chemical bonding that results from the electrical attraction between large numbers of anions and cations |
covalent bond | results from the sharing of elctron pairs between 2 atoms |
chemical compounds tend to form so that each atom, by gaining,losing or sharing electrons has an octet or 8 e's in its highest enrgy level | octet rule |
nonpolar | bonds where the electrons are shared equally by the bonded atoms resulting in a balanced distribution of electrical charge |
polar | covalent bond with an uneven distribution of electrical charges bc the bonded atoms have an unequal attraction for the shared electrons |
molecule | a neutral group of atoms held together by covalent bonds |
diatomic molecule | molecules containing 2 atoms |
chemical formula | indicates the relative numbers of atoms of each kind of element in a chemical compound by using atomic symbols and subscripts |
molecular formula | show the types and numbers of atoms combined ina single molecule of a molecular compound |
unshared pair | pair of electrons that is not involved in abonding and that belongs to only one of the atoms |
structural formula | formula indicates the kind, number, arrangement, and bonds but not the unshared pairs of electrons of the aotms in a molecule |
formula units | the simplest collection of atoms from which an ionic compound's formula can be established |
ionic compound | networks of positive and negative ions mutually attracted |
crystal lattice | the ordelry arrangement of ions in anionic compound |
metallic bond | the attraction betwen the metal's atoms and the surrounding sea of electrons |
sea of electrons | some nonesent about how electrons flow |
conversion factor | ratio or fraction in which the numerator is equivalent to the denominator so that it represnts |
oxidation number | the number of electrons lost, gained or shared by an atom creating a positive or negative charge |
binary compound | compound made of only 2 types of atoms |
nonbinary comound | compound made of more than 2 types of atoms and that includes at least 1 polyatomic ion |
empirical formula | indicates the smallest whole number ratio of the different atoms in the compound |
formula mas | for any molcule, formula unit, or ion, the formula mass is the sum of the atomic masses of all the atoms present in its formula |
percentage composition | the percentage by mass of each element in a compound |
6.022x10^-23 | avagadro's number |
molar mass | the mass of one mole of a pure substance |
mol | SI unite for the amount of substance |