chemical bonding Flashcards
how are chemical compounds formed?
they form when atoms are bonded together
- have low potential energy when atoms are bonded
endothermic
breaking a chemical bond
absorbs energy = cooler surroundings
exothermic
forming a chemical bond
release energy = warmer surroundings
low potential energy
compounds with strong stable bonds = dont release much energy when broken
high potential energy
compounds with weak + unstable bonds = release moore energy
what are the 2 kinds of compounds?
ionic (nonmetal + metal, cation +anion)
covalent
ionic compounds
high + boiling points, dissolves in water, conducts electricity in solution
covalent
low melting point + boiling point, DO NOT CONDUCT ELECTRICITY NOR DISSOLVE IN WATER
What is a chemical bond?
formed when valance electrons are transferred (ionic) or shared (covalent) between atoms
What is polarity?
distribution of electrons
polar = asymmetrical
non-polar = symmetrical
what happens when an atom gains an electron?
radius increases because electrons are further away from the nucleus
what happens when an atom loses an electron?
radius decreases = electrons closer to the nucleus
how do atoms become stable?
by ionic bonds donating electrons and covalent bonds sharing electrons
when are atoms stable
when they have a full valance shell (8 electrons)
exception: H only needs 2
electronegativity
atoms attractions to electrons
0.0-0.4
non polar covalent
0.4-1.7
polar covalent
higher than 1.7
ionic
intermolecular forces
attractive forces that increase between the molecules of substances (elements + compounds) and responsible for physical + chemical properties
hydrogen bonds
strong intermolecular forces
FON means..
fluorine, oxygen, nitrogen
substances with hydrogen bonds have…
high + boiling melting points
dipole dipole
type of intermolecular force
positive + negative molecule
do covalents share or donate?
share
