Which of the following elements is most likely to be dull and brittle?

• A. Sulfur (S)
• B. Copper (Cu)
• C. Magnesium (Mg)
• D. Sodium (Na)

Answer: (A)

Verified step by step guidance

1. Understand the properties of metals and nonmetals: Metals tend to be shiny, malleable, and ductile, while nonmetals are often dull and brittle.
2. Identify the type of each element: Copper (Cu), Magnesium (Mg), and Sodium (Na) are metals, whereas Sulfur (S) is a nonmetal.
3. Recall that metals have metallic bonding, which allows atoms to slide past each other without breaking, making them malleable and shiny.
4. Nonmetals like Sulfur have covalent or molecular structures that do not allow atoms to move freely, resulting in a dull appearance and brittleness.
5. Conclude that Sulfur (S), being a nonmetal, is most likely to be dull and brittle compared to the metallic elements listed.