Chapter 2

Question 1

the types of attraction between molecules

Answer 1

intermolecular forces
intramolecular forces

Question 2

intermolecular forces

Answer 2

forces that bond molecules together
also known as van der waals forces

Question 3

intramolecular forces

Answer 3

forces that bond the atoms within a molecule together
involved in the formation of true chemical bonds

Question 4

relative strength of inter and intra-molecular forces

Answer 4

intramolecular forces are 30-400x stronger than intermolecular forces

Question 5

2 major and 1 minor types of bonding

Answer 5

major: ionic and covalent
minor: metalic

Question 6

ionic bonding

Answer 6

bonding that involves yje transfer of electrons from 1 atom to anotehr to produce ions
resulting substances are held together by strong electrical attractions between + and - ions
forms ionic compounds (composed of metals and non metals) usually called salts or crystals
involves the transfer of electrons between valence shells of atoms
results in ionic compounds

Question 7

ion

Answer 7

an atom or group of atoms that carries iether a positive or negative charge
cation: positive charge, gives up electrons, metal
anion: negative charge, takes electrons

Question 8

formation of ionic compounds

Answer 8

ionic bonds form when one of the atoms is attracted to the electron pair much more strongly than the other atom, thus, the electron pair is pulled closer to that atom and away from the other

Question 9

electronegativity

Answer 9

the ability of an element to attract electrons

Question 10

properties of ionic compounds

Answer 10

• tend to form crystal lattices
  -high m.p and b.p
  -solid at room temp
  low volatilities
  -solid state is brittle
  -solid has poor conductivity of both electricity and heat because ions cant move
  -the liquid state has high conductivity as ions can move

Question 11

why is H2 more stable than 2 H atoms

Answer 11

whenever a bond is formed enegru is released that makes the things involved more stable than they were originally. the more bonds an atom can form the more energy is released, and the more stable the system becomes. in the case of H, there is only 1 atom to share so it can only form 1 covalent bond. The H2 molecule is still much more stable than 2 H atoms

Question 12

what gives substancs their phsyical propertiees

Answer 12

All elements have unique properties because of the bonding in the molecule, the result of this ranges form different boiling points, melting points to the ability to conducting electricity if there are electrons that can move.

Question 13

what gives a susbtance its chemical properties

Answer 13

Chemical properties of matter describe its potential to undergo some chemical change or reaction by its composition. the electron configuration of the elements involved, and, if any, bonds present.

Question 14

single bond

Answer 14

longest bond weakest bond

Question 15

double bond

Answer 15

in between single and triple in terms of strength and length

Question 16

triple bond

Answer 16

shortest bond, strongest bond

Question 17

why does more than 1 bond form

Answer 17

when atoms bond covalently, they do so in a way that forms the most number of bonds possible so that the final molecule is as stable as possible

Question 18

why is water more stable than 2 H and O

Answer 18

it costs energy to break bonds but a lot fo energy is released when new ones are made. the reaction between h and o is explosive. this is because more energy is released making new bonds than breaking old ones. because so much energy is released, H2O is more stable than a mixture of H and O

Question 19

what happens when metal atoms bond toegther

Answer 19

the outer electrons on each metal atom become free to move throughout the whole structure, they become delocalised. as the atoms lose electrons, positively charged metal ions are left behind, the attraction between each positive ion and the sea of delocalised elctrons make metals as a whole very hard with high mp and bp

Question 20

how do intermolecular forces arise

Answer 20

through sllight electrical distorions in molecules

Question 21

intermolecular forces during melting

Answer 21

heating gives the moelcule enough energy so that the intermolecular attractions arent strong enough to keep the molecules in a solid structure. once in liquid state, there are temporary attractions between water molecules the molecules can move because these forces of attraction are being broken and remade all the time

Question 22

intermolecular forces during boiling

Answer 22

attractions are totally disrupte dand the molecules become free to move around as gases. more heat makes the molecules move fast so the attractions cant hold them together anymore