Periodic Table

Question 1

what was Dalton’s theory

Answer 1

the atom was a solid sphere that was indestructible and all atoms of the same element were identical

Question 2

what was JJ Thomson’s theory called

Answer 2

the plum pudding model

Question 3

findings of Rutherford’s gold foil experiment

Answer 3

most particles passed straight through showing atom consisted of mainly empty space
few particles were deflected
few bounced back

Question 4

structure of an atom

Answer 4

consists of protons, neutrons and electrons

Question 5

atomic number

Answer 5

number of protons

Question 6

mass number

Answer 6

number of protons and neutrons

Question 7

what are isotopes

Answer 7

different atoms of the same element that have the same number of protons but different number of neutrons in their nuclei

Question 8

why isotopes have similar chemical properties

Answer 8

they have the same number of electrons in their outer shell

Question 9

2 ways isotopes are similar

Answer 9

same number protons in their nuclei

similar chemical properties

Question 10

2 ways isotopes are different

Answer 10

different physical properties

different number of neutrons in their nuclei

Question 11

what is relative atomic mass

Answer 11

average mass of an atom of an element relative ti 1/12th of the mass of an atom of carbon-12

Question 12

how did Mendeleev arrange his elements

Answer 12

in order of increasing relative atomic mass

Question 13

why did Mendeleev leave gaps

Answer 13

he assumed these elements had not been discovered yet and predicted the properties of some missing elements

Question 14

3 similarities between Mendeleev’s table and modern table

Answer 14

elements put into groups
elements put into periods
elements with similar chemical properties put in same groups

Question 15

what are group 1 metals called

Answer 15

the Alkali metals

Question 16

what are group 7 elements called

Answer 16

the halogens

Question 17

what are group 0 elements called

Answer 17

the noble gases

Question 18

what does the period number show

Answer 18

number of occupied electron shells

Question 19

what does group number show

Answer 19

number of electrons in the outer shell

Question 20

how are G1 metals stored and why

Answer 20

under oil to prevent them from reacting with oxygen in the air

Question 21

metal + water ——–>

Answer 21

metal hydroxide + hydrogen

Question 22

properties of G1 metals

Answer 22

low densities
very reactive 
white ionic solids 
low melting points 
soft
good conductors of electricity

Question 23

why reactivity increase as you go down group 1

Answer 23

as you go down the group, the atom gets bigger because there is one more shell of electrons. The outer electron is further away from the nucleus and is more shielded by the inner shells of electrons. The outer electron is less strongly attracted to the nucleus, so is lost more easily

Question 24

what do you observe when G1 metal is added to water

Answer 24

fizzing
metal melts and float on water
lilac flame for K, Rb, Cs

Question 25

test for hydrogen

Answer 25

test gas with a lighted splint, there will be a squeaky pop

Question 26

chemical properties of G1 metals

Answer 26

react with water to produce alkaline solution react with water, releasing hydrogen react with acids

Question 27

why is a lilac flame seen when potassium reacts with water

Answer 27

reaction is exothermic and hydrogen is produced. Heat energy given out ignites the hydrogen causing a lilac flame

Question 28

uses of transition metals

Answer 28

construction vehicles electrical wiring

Question 29

physical properties of transition metals

Answer 29

``` malleable ductile good conductors of electricity high melting points high densities shiny when polished ```

Question 30

chemical properties of transition metals

Answer 30

compounds are coloured more than 1 oxidation state catalysts

Question 31

why do halogens not conduct electricity

Answer 31

there are no free electrons

Question 32

what happens to the boiling points of halogens as you go down group and why

Answer 32

increase as larger molecules have larger forces of attraction between them , so intermolecular forces become stronger as you go down the group

Question 33

what happens to reactivity as you go down G7

Answer 33

atom get larger as there are more shells of electrons, so force of attraction between positive nucleus and incoming electron decreases. Reactivity decrease because it becomes more difficult for atom to form a negative ion

Question 34

test for chlorine gas

Answer 34

test gas with damp blue litmus paper. Litmus first turns red and then bleaches

Question 35

colour of bromine

Answer 35

orange

Question 36

colour of iodine

Answer 36

brown

Question 37

why are group 0 elements inert

Answer 37

they have a full outer shell of electrons so their atoms tend not to gain, share of lose electrons

Question 38

properties of group 0 elements

Answer 38

colourless gases at room temp single atoms very low MP and BP poor conductors of heat and electricity

Question 39

uses of helium

Answer 39

weather balloons and airships

Question 40

why is helium used in weather balloons

Answer 40

have low density and is non - flammable

Question 41

uses of argon

Answer 41

added to space above wine barrels lamps welding

Question 42

why argon is used in lamps and welding

Answer 42

to provide an inert atmosphere and to stop oxygen reacting with metal (oxidation) due to high temp

Question 43

use of neon

Answer 43

illuminated signs and lasers