Which is a characteristic of metals?

• A. Shiny
• B. Non-conductive
• C. Brittle
• D. Low density

Answer: (D)

Metals typically have a shiny appearance, called luster, because their surface electrons reflect light in a way that gives a bright, metallic shine. This reflects a common, recognizable property of metals. The other options don’t fit as well: metals are good conductors of electricity and heat, so being non-conductive isn’t characteristic; metals are generally malleable and ductile rather than brittle; and density varies widely among metals, with many being quite dense rather than having low density. So shininess best describes a typical metal property.