IGCSE Chemistry: Specimen Questions with Answers 237 - 238 of 240

Answer

c.

Explanation

While moving down a group in the modern periodic table, number of electronic shells of the atoms of the elements increases as a result of which size of the atom increases.

Let us consider group 1 as an example.

It can be observed that while moving down the group, number of electronic shells increases gradually. As the number of shells increases so the size of the atom increases.

Similarly it can be observed in all other groups that the number of shells increases gradually while moving down the group. So the size of the atom increases while moving down a group.

Explanation

You can test to see if a solution contains iodide ions by using silver nitrate. If silver nitrate solution is added to a sample of water containing iodine ions the silver halide is precipitated. This is because the silver halides are all insoluble in water.