Deck 1

Question 1

whats the most abundant element in the universe

Answer 1

hydrogen

Question 2

comment on melting and boiling points of hydrogen

Answer 2

very low melting and boiling points due to weak molecular forces

Question 3

where does hydrogen comes from

Answer 3

in the lab - reaction of acid with electropositive metals

electrolysis - passing electricity through water

Question 4

ionic hydrides

Answer 4

form with reactive metals where H has a -1 oxidation state

Question 5

covalent hydrides

Answer 5

form with nonmetals (H has a +1 oxidation state)

Question 6

what are the group 1 elements also known as

Answer 6

alkali metals

Question 7

why are the group 1 elements called this

Answer 7

they react with water to form alkaline solution

Question 8

why are they normally stored under oil

Answer 8

because they are so reactive.
only has one electron in their outer shell and easily lose their single valence electron (easily oxidized)

Question 9

what happens when alkali metals react with water

Answer 9

react violently with water to form MOH and release hydrogen gas

Question 10

what happens when group 1, Alkali Metals react with halogens

Answer 10

for salts of the form MX

eg. 2Na + Cl2 -> 2NaCl

Question 11

what happens when Alkali Metals react with Oxygen in the air

Answer 11

create oxide coating/tarnish

Question 12

Li2CO3

Answer 12

lithium carbonate
- drug for bipolar disorder
- used in manufacture of ceramics and toughened glass

Question 13

KNO3

Answer 13

potassium nitrate
- gunpowder and fireworks

Question 14

NaOH

Answer 14

sodium hydroxide
- used to make bleach
- important industrial base

Question 15

what are the group 2 elements also known as

Answer 15

alkaline earth metals

Question 16

compare group 1 and group 2

Answer 16

group 2 metals are harder and denser than group 1 metals

group 2 melting points are similar to group 1 boiling points

Question 17

what happens when group 2 elements react with oxygen

Answer 17

group 2 metals reduce oxygen to form oxides

Question 18

beryllium anomalous behaviour

Answer 18

• high charge density, Be polarizes nearby electron clouds
• can form bonds that are more covalent in character
• Be is electron deficient in linear structure (it doesnt fill its octect)

Question 19

why do the first members of each non metal group act different from the other group members

Answer 19

• smaller size
• greater ionization energy
• only have four valence orbitals

Question 20

what is the other name for group 13

Answer 20

Boron family

Question 21

whats different about Boron compared to the rest of group 13

Answer 21

boron is a semimetal
- black
- hard
- high melting point
- semiconductor - tends to form covalent bonds

Question 22

properties of the other group 13 elements

Answer 22

shiny
relatively soft
malleable
low melting

Question 23

inert pair effect

Answer 23

just losing 1 p electron can allow ……

Question 24

what is borohydride anion (BH4-) formed from

Answer 24

borane (BH3) with hydride (H-)

Question 25

amphoteric

Answer 25

can react with acid or base

Question 26

what are the group 14 elements also known as

Answer 26

carbon group

Question 27

talk about the variety of chemistry in the carbon group

Answer 27

non metals (carbon): solid covalent bonds, very high melting points

semimetals (silicon, germanium): weaker covalent bonds, high m.p

metals (tin and lead): metallic bonding, lower m.p

Question 28

carbon monoxide (CO)

Answer 28

produced in inefficient combustion
it is poisonous
binding to iron in hemoglobin

Question 29

carbonic anhydrase

Answer 29

catalysis the formation of carbonic acid in blood

Question 30

allotropes

Answer 30

different forms of elemental carbon

Question 31

why does graphite conduct electricity

Answer 31

there is delocalization of electrons in p orbital

Question 32

buckminsterfullerene

Answer 32

discrete C60 molecular units

Question 33

why do Si=Si bonds not usually occur

Answer 33

Si is larger than C and forms longer bonds

Question 34

key difference between C and Si

Answer 34

C forms unsaturated bond to give molecular gas and oxygen
Si forms tetrahedral networks

Question 35

what is the vital ingredient in semiconductors

Answer 35

silicon

Question 36

how can pure silicon be isolated

Answer 36

high temperature

Question 37

P-type doping

Answer 37

introducing a hole
replacing the Si with B, Al, Ga or In (they have less electrons)

Question 38

N type doping

Answer 38

adding group 15 donors (P, As, Sb and Bi)
resulting in an extra valence electron

Question 39

phosphorus allotropes

Answer 39

elemental phosphorus - extremely flammable

white phosphorus - P4 tetrahedra
if you heat it in 300 degrees Celsius with no air you get
red phosphorus

Question 40

phosphorus oxides

Answer 40

combustion of P4 gives phosphorus (III) oxide or phosphorus (V) oxide depending on whether there is excess oxygen

Question 41

how many valence electrons does group 16 (oxygen family) have

Answer 41

six valence electrons

Question 42

what are the group 18 elements also known as

Answer 42

noble gases

Question 43

talk about the boiling and melting points of group 18 elements

Answer 43

extremely low boiling and melting points, very limited intermolecular interactions holding them together

Question 44

applications of noble gases

Answer 44

helium: used to fill balloons and lighter then air craft
liquid helium: important coolant for superconductors and powerful magnets
neon: lights and signs

Question 45

reactivity of group 18

Answer 45

very limited due to full valence shells

exception: xenon gas has been shown to react upon heating with flourine gas.

Question 46

characteristics of molecular hydrogen (H2)

Answer 46

colourless and odourless gas

Question 47

Which main group element has a common molecular allotrope made of four atoms arranged at the corners of a tetrahedron

Answer 47

phosphorus

Question 48

what is the only halogen that is a liquid at room temperature

Answer 48

bromine