Question

select the pair of elements you would expect to have similar properties.
\bigcirc h and he
\bigcirc p and n
\bigcirc rb and sr
\bigcirc in and sn

Explanation:

Elements in the same group (vertical column) of the periodic table have similar properties because they have the same number of valence electrons. Let's analyze each pair:

• H (Hydrogen) is in Group 1, He (Helium) is in Group 18. Different groups, so properties differ.
• P (Phosphorus) and N (Nitrogen) are both in Group 15. They have the same number of valence electrons (5), so they should have similar properties.
• Rb (Rubidium) is in Group 1, Sr (Strontium) is in Group 2. Different groups, properties differ.
• In (Indium) is in Group 13, Sn (Tin) is in Group 14. Different groups, properties differ.

Answer:

B. P and N