Question

for each of the following sets of elements, identify the element expected to be most electronegative (circle) and which is expected to be least electronegative (cross out), based on their position in the periodic table. k sc ca br f at c o n

Explanation:

Step1: Recall electronegativity trend

Electronegativity increases across a period and decreases down a group in the periodic table.

Step2: Analyze K, Sc, Ca

K (potassium), Sc (scandium), Ca (calcium) are in the same period. K is the left - most, so it is least electronegative. Sc has a higher electronegativity than K and Ca.

Step3: Analyze Br, F, At

F (fluorine) is the most electronegative element in the periodic table. At (astatine) is below Br (bromine) in the same group, so At is least electronegative among them.

Step4: Analyze C, O, N

O (oxygen) is to the right of C (carbon) and N (nitrogen) in the same period, so O is most electronegative. C is to the left - most among them, so C is least electronegative.

Answer:

For K, Sc, Ca: Cross out K, circle Sc.
For Br, F, At: Cross out At, circle F.
For C, O, N: Cross out C, circle O.