9. The Periodic Table

Question 1

Periodic table

Answer 1

an arrangement of elements in periods and groups and in order of increasing proton number/ atomic number.

Question 2

Describe the change from metallic to
non-metallic character across a period and change in metallic character down the group

Answer 2

increase in the no. of outer shell electron so atoms readily accept electrons to fill their outer shell.

increases down the group as electrons become easier to lose as outer shell electrons become further from nucleus so less attraction.

Question 3

Describe the relationship between group number and the charge of the ions formed from elements in that group and explain similarities in the chemical properties of elements in the same group

Answer 3

no. of group= no. of outer shell electron.
no. of period= no. of occupied shells

they have same no. of electrons in outer shell so similar chemical properties.

Question 4

Group I properties

Answer 4

P- softer
Low MP- decreasing
Low density- increasing
increasing reactivity
shiny surface when cut with knife

C- 1. burn in O2 with characteristic flame colors forming oxides
2. react vigorously with water to form hydroxides and hydrogen
3. react vigorously with halogens to form hallides

Question 5

Group VII

Answer 5

diatomic
MP- increasing
density- increasing
decreasing reactivity

1. react with metals- metal hallides
2. react with hydrogen- hydrogen hallides which dissolve in water to form acidic solutions.

Question 6

Group VII state and colours

Answer 6

fluorine- gas- pale yellow
chlorine- gas- pale yellow-green
bromine-liquid- red-brown
iodine- solid- grey-black
Astatine- solid- black

Question 7

Transition elements

Answer 7

high densities
high melting points
harder

coloured compounds
act as catalysts
variable oxidation numbers
form complicated ions

Question 8

Noble gases

Answer 8

Unreactive- full outer shell
monoatomic
colourless