The Periodic Table and Group Trends: Question 1

Worked solution

Step 1: Recall how group number relates to ionic charge

For elements in Groups I, II and III, the group number tells you how many electrons an atom loses when it forms an ion, and therefore the size of the positive charge on that ion.

• Group I metals lose 1 electron $\rightarrow$ ions with charge $1+$
• Group II metals lose 2 electrons $\rightarrow$ ions with charge $2+$
• Group III metals lose 3 electrons $\rightarrow$ ions with charge $3+$

Step 2: Apply the rule to element T

Element T is in Group II, so an atom of T has 2 electrons in its outer shell. When T reacts with a non-metal, it loses these 2 outer electrons to achieve a stable, full outer shell.

Losing 2 negatively charged electrons leaves the ion with an overall charge of $\boxed{2+}$.

Why the other options are wrong

• A ($1+$): this is the pattern for Group I metals (losing 1 electron), not Group II.
• C ($1-$): a negative charge would mean T gains an electron, but metals lose electrons, they do not gain them.
• D ($2-$): this magnitude matches, but the sign is wrong, metals form positive ions, not negative ions.

Final answer

• The ion formed by element T has a charge of $\boxed{2+}$, option B.