Which of the following best describes the properties of metalloids on the periodic table?

• A. They have properties intermediate between metals and nonmetals.
• B. They are excellent conductors of electricity and heat.
• C. They are highly reactive and form ionic compounds with metals.
• D. They are generally brittle and do not conduct electricity.

Answer: (A)

Verified step by step guidance

1. Understand that metalloids are elements found along the 'stair-step' line on the periodic table, which separates metals and nonmetals.
2. Recall that metalloids exhibit properties that are intermediate between those of metals and nonmetals, meaning they can have characteristics of both.
3. Recognize that metalloids are not typically excellent conductors like metals, nor are they as poor conductors as most nonmetals; their conductivity is moderate and can vary under different conditions.
4. Note that metalloids do not generally form ionic compounds with metals as highly reactive metals do; their chemical behavior is more complex and can include covalent bonding.
5. Conclude that the best description of metalloids is that they have properties intermediate between metals and nonmetals, which explains their unique position and behavior on the periodic table.