Which of the following physical properties is commonly used to classify an element as a metal?

• A. High electrical conductivity
• B. Poor heat conduction
• C. Low melting point
• D. Brittleness

Answer: (A)

Verified step by step guidance

1. Understand that metals have characteristic physical properties that distinguish them from nonmetals and metalloids.
2. Recall that metals typically have high electrical conductivity because their electrons are free to move throughout the metal lattice, allowing electric current to flow easily.
3. Recognize that metals generally have good heat conduction, so 'poor heat conduction' is not a property of metals.
4. Note that metals usually have relatively high melting points compared to nonmetals, so 'low melting point' is not typical for metals.
5. Remember that metals are malleable and ductile, meaning they are not brittle; brittleness is more common in nonmetals.