Chapter 18 Flashcards
how does the way that atoms combine to form compounds w/ different properties depend on their positions in the periodic table?
metals tend to be more reactive than nonmetals, and because metals are very close together within the periodic table, their compounds tend to be ionic. on the other hand, nonmetals tend to have combine through covalent bonds because of their lack of reactivity.
how do atoms form ionic and covalent bonds?
ionic: by transferring electrons
covalent: by sharing electrons
in terms of stability, what happens to individual atoms when they form compounds?
each atom is more stable in the compound than it was by itself
a compound that has water chemically attached to its atoms and written into its chemical formula
hydrate
a positively or negatively charged, covalent bonded group of atoms
polyatomic ion (think: what does the prefix ‘poly’ mean?)
ionic compounds composed of two elements
binary compounds (think: what does the prefix ‘bi’ mean?)
a positive or negative number that indicates how many electrons an atom has gained, lost, or shared to become stable
oxidation number (shown next to ions; ex. 1+ and 1- if one electron was transferred from former atom to latter)
a molecule that does not have oppositely charged ends
nonpolar molecule (results from nonpolar covalent bond)
a molecule in which the unequal sharing of electrons results in a slightly positive end and a slightly negative end, although the overall molecule is neutral.
polar molecule (molecule resulting from polar covalent bond)
a bond in which electrons are shared unequally, resulting in a slightly positive end and a slightly negative end.
polar bond (instance where one atom attracts more electrons than the other, offsetting the charge)
a covalent bond in which electrons are shared equally by both atoms
nonpolar bond (occurs when atoms aren’t more attracted to one nucleus in the bond, so electrons are shared equally)
the neutral particle that forms as a result of electron sharing is called a…
molecule
covalent bonds most frequently occur between which of the following: metals, nonmetals, or metalloids?
nonmetals. these are unlikely to lose or gain electrons (meaning they’re less reactive than, say, metals,) so they stabilize by sharing electrons with similar elements.
the attraction that forms between atoms when they share electrons
covalent bond
compare and contrast ionic bonds and chemical bonds (REMEMBER: BONDS!!!!)
a chemical bond describes the force of attraction between two ATOMS of different ELEMENTS; in order for one to form, these two atoms will transfer electrons between their outer layers until they’re filled.
an ionic bond describes the force of attraction between two IONS of different CHARGES. these form as a result of a chemical bond, given that they must equal each other. (when electrons are transferred between atoms, positive and negative ions form; these ions must cancel each other out to form a neutral particle.)
