S 2.1

to decrease their potential energy, into a lower, more stable energetic state this done by attaining a full outer electron shell

Low electronegativity interacting with high electronegativity

both atoms have middle-to-high

both atoms have low electronegativity

metals - low non-metals - high/middle to high

rule of thumb to predict a type of bond if electronegativity difference is over 1.7, it is ionic if it is under 1.7, it is covalent

a relative measure of the attraction of an atom for a pair of electrons (in a covalent bond)

effective nuclear charge atomic radius

effective nuclear charge

the electrostatic force of attraction between oppositely charged ions causes them to pack into the ionic lattice with every cation surrounded by anions/vice verse

because it has formed through the loss of its valence shell

increased repulsion between electrons decreased attraction between nucleus and valence shell electrons

cation smaller than anion

covalent groups of oxygen and another non-metal

• conduct when molten or in solution, ions feee to move and pass to electrodes in electrolysis • high m.p and b.p • hard and brittle • more soluble in polar than non-polar solvents

• the energy required to break up 1 mole of an ionic lattice into gaseous ions under standard conditions • measures stability and strength of an ionic lattice

endothermic - positive

size of the ions - the smaller they are, the more closely they can pack together and attract each other charge on the ion - the ore charged it is, the stronger the electrostatic force of attraction

charge on cation x charge on anion/sum of ionic radii

The electrostatic attraction between oppositely charged ions

in 3d ionic lattice structures

NH4 +

OH-

NO3 -