Question

fluorine sodium phosphorus magnesium

Explanation:

To solve this, we analyze the valence electrons (dots) and match with the elements:

Step 1: Analyze the first electron - dot structure (1 dot)

Sodium (Na) is in Group 1, so it has 1 valence electron. The first structure has 1 dot, so it matches sodium.

Step 2: Analyze the second electron - dot structure (2 dots)

Magnesium (Mg) is in Group 2, so it has 2 valence electrons. The second structure has 2 dots, so it matches magnesium.

Step 3: Analyze the third electron - dot structure (7 dots)

Fluorine (F) is in Group 17, so it has 7 valence electrons. The third structure has 7 dots, so it matches fluorine.

Step 4: Analyze the fourth electron - dot structure (5 dots)

Phosphorus (P) is in Group 15, so it has 5 valence electrons. The fourth structure has 5 dots, so it matches phosphorus.

Answer:

First box: sodium
Second box: magnesium
Third box: fluorine
Fourth box: phosphorus