chemical bonding

what is a bond?

a pull that keeps atoms and ions stuck together.

what is the purpose of a bond?

to lower the system's potential energy and stabilize the atoms involved.

covalent bond

Two nonmetals share electrons, so their valence shells are full.

polar covalent bonds

Nonmetals share electrons unequally when electronegativities differ.

Ionic Bond

a bond that results from the transfer of electrons from a low electronegative atom to a higher electronegative atom

metallic bonds

bonds between metals with electrons that are distributed and shared equally among all atoms

octet

8 electrons in an atoms outer shell (before valence shell)

bonding and an octet

goal for ionic and covalent bonding is to gain an octet

s and p block…

always obey octet rule

octet rule

atoms gain, lose, share, electrons, to achieve stable configuration with 8 valence electrons.

metal=

ionic

non metal=

covalent

opposite charges…

hold ions together.

electronegativity

a atoms tendency to attract shared electrons in a chemical bond

shared electrons

valence electrons that are attracted to the nuclei of 2 or more atoms

endothermic

energy is added to a reaction (feels cold)

exothermic

energy is removed/released (feels hot)

bonded atoms

have lower energy than individual atoms do

formation of ionic bonds

exothermic

electrostatic attraction

force that draws objects together with opposite electrical charges 

lattice energy

energy required to separate a mole of solid ion compound into gas ion

reverse lattice energy

formation of a bond

Large LE

strong attraction of ions

coulombs law

the electric force between two charged objects is stronger when the charges are bigger and weaker when they are farther apart

smallest ions with largest charge

high LE

largest ions with smallest charge

low LE

energy released from compounds with large charge 

more exothermic

Zeff

actual amount of positive charge from the nucleus that a specific electron "feels"

endothermic process

anything that absorbs heat (thermal energy) from its surroundings. 

ionization energy

the minimum energy required to remove an electron from a gaseous atom or ion

dipole

a system with two opposite, equal charges separated by a distance

nonpolar covalent bonds

electronegativity values are equal