chapter 2 - the periodic table

Question 1

how many elements in the periodic table

Answer 1

118 elements

Question 2

how did Dimitriv Mendeleev arrange the P.T

Answer 2

arranged by atomic mass and organised them into groups and periods due to the realisation of similar chemical properties

Question 3

how are chemical properties determined

Answer 3

by the outer shell electrons

Question 4

periods

Answer 4

• are horizontal groups

- corresponds to the filling of a shell eg. a period 3 element has three electron shells

Question 5

groups

Answer 5

• vertical columns

- the group no. corresponds to the number of valence electrons eg. period2 element has 2 valence electrons

Question 6

where are the s-block elements

Answer 6

group 1 and 2 including helium

• group 1 elements have outer shell s1
• group 2 elements have outer shell s2

Question 7

where are the p-block elements

Answer 7

group 13-18

- the elements have their valence electrons in the p sub-shell, going across to 6 at g18

Question 8

where are the d-block elements

Answer 8

group 3-12, transition metals

- these elements have their valence electrons progressively filled in the d sub-shell

Question 9

where are the f-block elements

Answer 9

the lanthanoids and actinoids

- have valence electrons in the f sub-shell

Question 10

what is core charge/nuclear charge

Answer 10

is a measure of the attractive force felt by the valence shell electrons towards the nucleus

Question 11

how to calculate core charge

Answer 11

protons - inner shell electrons

Question 12

across a period core charge

Answer 12

increases

Question 13

down a group core charge

Answer 13

remains constant

Question 14

what is the shielding effect

Answer 14

going down a group there is more shells being filled, these filled shells act as shields

Question 15

across a period the shielding effect

Answer 15

remains constant

Question 16

down a group the shielding effect

Answer 16

increases

Question 17

ionisation energy

Answer 17

• increases across a period

- increases up a group

Question 18

electronegativity

Answer 18

• increases up a group

- increases across a period

Question 19

atomic radius

Answer 19

• increases down a group

- increases from right to left across a period

Question 20

metallic character

Answer 20

• the most reactive/metallic element is francium

- the least reactive/metallic elements is helium

Question 21

G1 & G2 are the

Answer 21

alkali earths

Question 22

G17 are the

Answer 22

halogens

Question 23

G18 are the

Answer 23

noble gases