c1 - atomic structure and the periodic table

Question 1

size of atom

Answer 1

1x10 -10m

Question 2

radius of a nucleus

Answer 2

1 x 10 -14m

Question 3

why do atoms have no overall charge

Answer 3

the relative charge for an electron is -
and proton is +
number of electrons = number of protons

Question 4

what is mass number

Answer 4

total number of neutrons and protons

Question 5

avogados constant

Answer 5

6.02 x 10^23

Question 6

what is atomic number

Answer 6

number of protons

Question 7

electron shell limits

Answer 7

2,8,8,2

Question 8

what is an isotope

Answer 8

Atoms of the same element can have different numbers of neutrons

Question 9

abundance equ

Answer 9

(isotopic mass number x abundance) + (isotopic mass number x abundance) divided by 100

Question 10

jj thomson plum pudding model

Answer 10

A ball of positive charge with electrons embedded inside.

Question 11

how did rutherford prove the plum pudding model was wrong

Answer 11

Alpha particle scattering experiment.

Fired positive alpha particles at gold foil.

Most particles passed straight through = mainly empty space.

Only a few were deflected back = small positively charged centre where mass is

Question 12

what did bohr do to the nuclear model

Answer 12

electrons orbit the nucleus
at specific distances from the nucleus

Question 13

what is an element

Answer 13

made of only 1 type of atom. Found in the periodic table

Question 14

what is a compound

Answer 14

2 or more elements chemically joined together in a fixed ratio.

Question 15

what is a mixture

Answer 15

2 or more elements or compounds, not chemically joined.

Question 16

How would you extract salt from a sand and salt solution?

Answer 16

Filter to remove the sand.
Evaporate to remove the water.

Question 17

Separating mixtures

Answer 17

Filtration

Chromatography

Distillation

Question 18

newlands development of the periodic table

Answer 18

Ordered by atomic weight
Elements were therefore in wrong groups
Metals were in groups with non metals

Question 19

mendeleev development of the periodic table

Answer 19

Ordered in atomic weight but changed it so elements are in groups with similar properties

Left gaps for undiscovered elements

When elements were discovered, they had properties which matched Mendeleev’s predictions

Question 20

why did mendeleevs periodic table become more widely accepted

Answer 20

predicted properties of missing elements
elements were discovered
they matched his predictions

Question 21

properties of alkali metals

Answer 21

Soft
Low density
Low melting and boiling points
Very reactive
Form white compounds

Question 22

alkali metals reactions with water

Answer 22

produce hydrogen and a metal hydroxide solution.

Question 23

alkali metals reactions with oxygen

Answer 23

oxides

Question 24

alkali metals reactions with chlorine

Answer 24

chlorides

Question 25

group halogens

Answer 25

less reactive as you go down less volality less solubility melting and boiling decrease

Question 26

Group 7 Halogens reactions:

Answer 26

The chlorine displaces the bromide as it is more reactive than bromine

Question 27

why is there a higher boiling point

Answer 27

relative formula mass increases so intermolecular forces increase in strength more energy is needed to overcome

Question 28

why do elements in the same group react in a similar way

Answer 28

same number of electrons in the outer shell

Question 29

group 0 chemical properties

Answer 29

Inert (unreactive due to full outer shell). Non-flammable Colourless gases at room temperature. Boiling point increases

Question 30

properties of transition metals

Answer 30

Form ions with different charges Different coloured compounds Used as catalysts Unreactive Strong High density High melting points Hard Good conductors of electricity Good thermal conductors