Question

the electron dot diagram for an unknown element x is shown. what element could this diagram represent?
a. chlorine
b. magnesium
c. phosphorus
d. silicon
e. sulfur

Explanation:

Electron dot diagrams (Lewis dot structures) show the valence electrons of an atom. The diagram here has 5 valence electrons (since there are 5 dots). Let's analyze each option:

• A. Chlorine (Cl): Group 17, has 7 valence electrons. Eliminate.
• B. Magnesium (Mg): Group 2, has 2 valence electrons. Eliminate.
• C. Phosphorus (P): Group 15, has 5 valence electrons. Matches the dot diagram.
• D. Silicon (Si): Group 14, has 4 valence electrons. Eliminate.
• E. Sulfur (S): Group 16, has 6 valence electrons. Eliminate.

Answer:

C. phosphorus