Metals and non-metals in the periodic table
3 marks · EasyThis question is about group trends in the periodic table.
State how many electrons a typical Group 7 element has in its outer shell.
Explain why the elements fluorine and bromine have similar chemical properties.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) 7
(b) Fluorine and bromine both have 7 electrons in their outer shell, so they react in similar ways. · must show States they have the same number of outer shell electrons, Links this to similar chemical properties or reactions
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States that a Group 7 element has 7 electrons in its outer shell.
M1 (b) · 1 mark · Identifies that both fluorine and bromine have the same number of electrons in their outer shell.
M2 (b) · 1 mark · Explains that having the same number of outer shell electrons makes their chemical reactions similar.
Worked solution
a) There are 7 electrons in the outer shell of a Group 7 element.
b) Fluorine and bromine both have 7 electrons in their outer shells. This causes them to react in similar ways because the number of outer shell electrons determines the chemical properties of an element.