16
17
18
19
Answer is Right!
Answer is Wrong!
The periodic table contains 18 groups. Groups are vertical columns in the periodic table. Elements in the same group have similar chemical properties. For example, all of the elements in group 1 are metals that are very reactive and form strong bases. All of the elements in group 18 are noble gases that are very unreactive.
Option A: 16 is incorrect because there are 18 groups in the periodic table.
Option B: 17 is incorrect because there are 18 groups in the periodic table.
Option C: 18 is correct because there are 18 groups in the periodic table.
Option D: 19 is incorrect because there are 18 groups in the periodic table.