Bonding

Question 1

definition of ionic bonding

Answer 1

the strong electrostatic forces of attraction between oppositely charged ions to form the electron configuration of a noble gas

this occurs between metals and non metals

Question 2

what do ions arrange themselves into

what is each ion in it attracted to

Answer 2

a giant ionic lattice

attracted to the oppositely charged electrons

Question 3

what is one property of ionic compounds regarding mp/bp

Answer 3

they are solids at room temperature as they have very high melting and boiling points due to strong electrostatic forces of attraction within each oppositely charged ions in the giant ionic lattice. it takes a lot of energy to overcome the strong electrostatic forces of attraction

Question 4

can ionic compounds conduct electricity?

Answer 4

they will not conduct electricity in a solid state as the ions are not free to move. they will conduct electricity when molten / aqueous

Question 5

what are ionic compounds like density wise and why?

Answer 5

they are brittle

because they can easily shift layers, then the like ions (charges) will line up and repel

Question 6

what 2 things increases the strength of ionic bonds ?

Answer 6

1) the greater ionic charge of the ions

2) the smaller the ionic radius

Question 7

what is a covalent bond

Answer 7

a covalent bond is a shared pair of electrons between two non-metal atoms

Question 8

how can a shared pair of electrons form a bond

Answer 8

the shared pair of electrons are attracted to the protons in the 2 nuclei , forming a covalent bond

Question 9

what are atoms that are not part of covalent bonds called

Answer 9

lone pair of electrons

Question 10

what is dative/coordinate bonding?

Answer 10

when an atom uses a lone pair of electron’s to form a covalent bond with an atom which has a vacant orbital

Question 11

how do we represent a dative bond

Answer 11

an arrow

Question 12

what must the atom donating the electrons have?

Answer 12

a lone pair of electrons (2 electrons not used in bonding)

Question 13

what must the atom receiving the electrons in dative bonding must have ?

Answer 13

a vacant orbital

Question 14

is a dative covalent bond the same as a normal covalent bond

they have the same…

Answer 14

yes

the same average bond enthalpy

(tells us the strength of the bond)

Question 15

what is electronegativity

Answer 15

the ability/power of an atom to attract a pair of electrons in a covalent bond

Question 16

what happens when the covalent bond consists of 2 atoms of the same element?

Answer 16

the shared pair of electrons are attracted to the nuclei equally

Question 17

why are noble gases not included in the electronegativity scale?

Answer 17

because they are unreactive

Question 18

what is electronegativity based on

what is the highest number for electronegativity

Answer 18

the pauling electronegativity scale

4

Question 19

what 3 factors does electronegativity depend on?

Answer 19

1) the size of the positive charge in the nucleus, moving left to right the number of protons increases which increases the attraction between nucleus and pair of electrons in the covalent bond

2) the atomic radius, from left to right the atomic radius decreases which means the closer the shared pair of electrons will be to the nucleus

3) shielding of nucleus by electrons in the inner shells, they screen the electrons in the outer shell from the positive charge in the nucleus

Question 20

what’s a dipole

Answer 20

a bond or molecule that has a difference in charge caused by a shift in electron density

Question 21

how to we show if a bond is polar

Answer 21

delta
+ -

Question 22

what is metallic bonding

Answer 22

strong electrostatic forces of attraction between positive metal ions and the sea of delocalised electrons

Question 23

what factors affect the strength of metallic bond

Answer 23

1) the ionic charge on the metal (higher =stronger metallic bonds)

2) number of delocalised electrons

3) the atomic radius (smaller = stronger )

Question 24

3 properties of metals

Answer 24

good conductors of electricity

high melting and boiling points

metals are malleable and ductile (layers of ions

Question 25

what does covalent bonding lead to the formation of

Answer 25

the formation of either simple or giant molecules

Question 26

name 3 types of intermolecular forces in order of strength

Answer 26

1) van der waals forces between molecules 2) permanent dipole-dipole forces between molecules 3) hydrogen bonding between molecules

Question 27

what’s van der waals forces

Answer 27

electrons are constantly moving from place to place so charge can change distributed at any time this means one side of the molecule can suddenly become more negative than the other side if the electrons have moved closer to that side (this is called a temporary dipole )

Question 28

how will a temporary dipole affect the neighbouring atoms and charge spread (van der walls forces)

Answer 28

a temporary dipole in one molecule induces a dipole in the neighbouring molecules as it repels the electrons to the other side (induced dipole) now there is a force of attraction between the $+ $- called van der waal forced

Question 29

what intermolecular force do all molecules have

Answer 29

van der waal force

Question 30

what affects the size of van der waal forces? (2)

Answer 30

* size/mr of the molecule (bigger molecule=more van der waals forces between molecules) * surface area contact

Question 31

what is permanent dipole-dipole forces between molecules

Answer 31

it only occurs between molecules which are polar (a polar bond is a difference in electronegativity between atoms there is a attraction between the oppositely charged deltas on the neighbouring molecules

Question 32

what is hydrogen bonding

Answer 32

this is very similar to permanent dipole-dipole bonding however this only occurs with polar molecules which have hydrogen directly bonded to nitrogen , oxygen and fluorine this is because they are the most polar molecules hydrogen and these elements have a huge difference in electronegativity and as a result pull the pair of electrons in the covalent bond very strongly towards themselves this leaves hydrogen very delta positive the lone pair of electrons in the neighbouring molecule containing nitrogen, oxygen and fluorine is then attracted to the hydrogen