Question

question 4. which of the following diagrams has arrows that point in the direction of increasing atomic radius?

Explanation:

Step1: Recall atomic radius trends

Atomic radius increases down a group (vertical) and decreases across a period (horizontal, left to right). So arrows should point down (for group) and left (for period) to show increasing radius.

Step2: Analyze each diagram

• First diagram: Vertical arrow down (good, increases down), horizontal arrow right (bad, radius decreases right).
• Second diagram: Vertical arrow up (bad, radius decreases up), horizontal right (bad).
• Third diagram: Vertical arrow down (good), horizontal arrow left (good, since radius increases left to right? Wait, no—wait, across a period, left to right, radius decreases. So to show increasing, horizontal arrow should be left (since left has larger radius than right). Vertical arrow down (larger radius down). So third diagram: vertical down (increasing) and horizontal left (increasing, as left is larger than right).
• Fourth diagram: Vertical up (bad) and horizontal left (but vertical is wrong).

Wait, recheck: The third diagram (the one with vertical down and horizontal left) matches: down a group (increases) and left across a period (since left has larger radius than right, so arrow left shows increasing from right to left). The first diagram's horizontal is right (decreasing), second vertical up (decreasing), fourth vertical up (decreasing). So the third diagram (the one with vertical red arrow down and horizontal red arrow left) is correct. Looking at the options, the third diagram (the one with the left - pointing horizontal arrow and down - pointing vertical arrow) is the correct one. From the image, the third diagram (the third in the list, with vertical down and horizontal left arrows) is the one where arrows point to increasing atomic radius.

Answer:

The third diagram (the one with the vertical arrow pointing down and the horizontal arrow pointing left)