Question

rank the following atoms in order of decreasing metallic behavior (i.e. most to least).
○ n > si > al > ca
○ al > ca > si > n
○ ca > al > si > n
○ ca > si > al > n

Explanation:

Step1: Recall metallic behavior trend

Metallic behavior increases down a group and decreases across a period (left to right).

Step2: Identify positions of elements

• Calcium (Ca) is in Group 2, Period 4.
• Aluminum (Al) is in Group 13, Period 3.
• Silicon (Si) is in Group 14, Period 3.
• Nitrogen (N) is in Group 15, Period 2.

Step3: Compare metallic behavior

• Down a group: Ca (Period 4) has more metallic behavior than elements in lower periods (Al, Si in Period 3; N in Period 2).
• Across Period 3: Al (Group 13) > Si (Group 14) (metallic behavior decreases left to right).
• N is a non - metal, least metallic. So order: Ca > Al > Si > N.

Answer:

Ca > Al > Si > N (the third option: Ca > Al > Si > N)