Strontium and barium have similar chemical properties because atoms of these elements have the same number of 1.protons
2.neutrons
3.electron shells
4. Valence electrons

4. Valence electrons

Explanation:

Strontium and barium have similar chemical properties because atoms of these elements have the same number of valence electrons.

The valence electrons are the outer shell electrons within an atom. Both strontium and barium belongs to the group of alkali -earth metals on the periodic table.

This group consists of elements with two valence electrons.

The number of valence electrons determines chemical properties.

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one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.