Siamese twins

Question 1

what do bonds between atoms always involve

Answer 1

outer electrons

Question 2

why are noble gases very unreactive

Answer 2

because their outer main levels are full so have no need to react

Question 3

why do atoms bond together

Answer 3

they will share or transfer electrons to gain a more stable electron configuration like noble gases - be jelly!!!

Question 4

what is ionic bonding between

Answer 4

between oppositely charged ions and they will transfer their electrons from metal to non metal shells to obtain the full main outer level

Question 5

what will happen as a result of ionic bonding

Answer 5

the metal will become positively charged - looses an electron - cation

the non- metal will become negatively charged gains the electrons from the metal - an anion

Question 6

what force joins ionic compounds together

Answer 6

electrostatic forces of attraction

Question 7

what are some properties of ionic compounds

Answer 7

• solids at room temp
• brittle - this is because of the oppositely charged ions and a blow in the wrong direction could cause the ions to come into contact that have like charged
• only conduct electricity when molten

Question 8

why are ionic compounds solids at room temp

Answer 8

because of their macromolecular ionic lattice and the large electrostatic forces of attraction between the ions the amount of energy required to overcome these forces is so large so it will remain solid until large amount of energy is applied.

Question 9

why can ionic compounds only conduct elec when molten

Answer 9

because when in their giant ionic lattice delocalised electrons are not free to move throughout the structure but when it becomes molten or aqueous the soltion provide a place for delocalised electrons to carry charge

Question 10

what is a covalent bond

Answer 10

bonding between a shared pair of electrons in a non-metal

Question 11

what is the force of attraction between the nucleus and the electrons called

Answer 11

electrostatic

Question 12

what are properties composed of molecules

Answer 12

low bpt and mpt - this is because strong covalent bonds are only between the atoms WITHIN MOLECULES
- poor conductors of elec - because the molecules are overall neutral and there are no delocalised electrons to carry charge throughout no structure!

• even if the molecules dissolve into an aqueous solution they will not comduct elec because the molecules will remain molecules

Question 13

what is co-oordinate bonding

Answer 13

in most covalent bonding the shared pair of electrons will come from both atoms but in coordinate bonding it comes only from one atom

Question 14

what is a lone pair in coordinate bonding

Answer 14

the atom that is donating a pair of electrons to an electron deficient atom will donate a LONE PAIR to complete the outer shell

Question 15

will coordinate bonding affect the shape of an molecule

Answer 15

no, though the electrons are only gifted from one atom the shape will be unaffected

Question 16

where will the arrow in coordinate bonding go from to?

Answer 16

from the lone pair to where it is going

Question 17

what is the only difference between coordinately bonded covalent bonds and covalent bonds

Answer 17

coordinate bonds are charged whereas the covalent bonds are not

Question 18

what is metallic bonding

Answer 18

a lattice of positive ions existing in a sea of outer electrons - these outer electrons are delocalised which means they are not tied to a particular atom and so area ble to carry charge easily throughout the structure

Question 19

what does the number of delocalised electrons in the sea of electrons depend upon

Answer 19

how many electrons have been lost by each metal atom

Question 20

what are properties of metals

Answer 20

• good conductors of heat and electricity
• malleable - can be beaten into shape
  ductile - can be pulled into thin wires
  metals are ductile nad malleable because after small distortion ecah metal ion is still in the same environment so the new shape will be retained

high mpt - because they have a giant structures and there is a strong attraction between the metal ions and the delocalised sea of electrons which will make the atoms difficult to separate

Question 21

define electronegativity

Answer 21

the power of an atom to attract the electron density towards itself within a covalent bond

Question 22

define polarity

Answer 22

the equal sharing of electrons that are bonded together covalently

Question 23

which factors will affect electronegativity

Answer 23

• nuclear charge
• the distance between the nucleus and the outer shell
  shielding of the nuclear charge by electrons in the inner shell.

Question 24

what is the trend in electroneg

Answer 24

increases across a period and up a group so the most electronegative element is fluorine 4.0 woohoo

Question 25

what can a difference in electronegativity cause

Answer 25

a dipole

Question 26

what is a dipole - may you ask

Answer 26

a difference in charge between two atoms caused by a shift in electron density

Question 27

are electrons static

Answer 27

noo - electrons are constantly moving in their electron clou thi is how you achieve van der waals and induced dipoles

Question 28

what does a molecule having a permanent or induced dipole depend upon

Answer 28

its shape and polarity

Question 29

what is a symmetric molecule???

Answer 29

all bonds are identical and no lone pairs. will not be polar even if individual bonds are polar. the individual dipoles can cancel out… the negatives will all cancel and positives can cancel it is not nessacerialy in equilibrium Cl4 see google for more you poor sod

Question 30

who came up with the electroneg scale

Answer 30

pauling