The Periodic Table
6 marks · NormalThis question is about electronic configurations, the periodic table, and how elements are classified as metals or non-metals.
Element J has the electronic configuration 2,8,7.
State:
The group number and period number of element J.
Whether element J is a metal or a non-metal.
Element K is in Group 1 and Period 3 of the periodic table.
State:
The electronic configuration of element K.
Whether the oxide of element K is likely to be acidic or basic.
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(a(i)) Group 7, Period 3
(a(ii)) Non-metal
(b(i)) 2,8,1
(b(ii)) Basic
Common mistakes: Matching group number to the wrong shell; Confusing metals and non-metals' positions; Incorrect oxide character for a Group 1 element
Show mark scheme and worked solution
Marking points
M1 (a(i)) · 1 mark · Relates the number of outer shell electrons to the group.
A1 (a(i)) · 1 mark · Gives both correct group and period numbers.
B1 (a(ii)) · 1 mark · Correctly identifies element J as a non-metal.
M2 (b(i)) · 1 mark · Uses group and period to deduce electronic configuration.
A2 (b(i)) · 1 mark · Gives correct configuration: 2,8,1.
B2 (b(ii)) · 1 mark · Identifies the oxide as basic.
Worked solution
a(i): The electronic configuration 2,8,7 means 7 electrons in the outer shell (so Group 7). There are 3 occupied shells, so Period 3.
a(ii): Elements in Group 7 are non-metals.
b(i): Group 1 and Period 3 means it has 3 shells and 1 electron in the outer shell: 2,8,1.
b(ii): Group 1 elements are metals and their oxides are basic.