Which statement best describes how the properties of elements compare to the properties of the compounds they form?

• A. The properties of compounds are identical to those of the most abundant element in the compound.
• B. The properties of compounds are usually very different from the properties of the elements that compose them.
• C. Compounds have properties that are a simple average of the properties of their constituent elements.
• D. Compounds always have the same properties as the elements that make them up.

Answer: (B)

Verified step by step guidance

1. Understand that elements are pure substances consisting of only one type of atom, each with its own unique set of properties such as melting point, reactivity, and color.
2. Recognize that compounds are substances formed when two or more elements chemically combine in fixed ratios, resulting in new substances with properties different from the individual elements.
3. Recall that the chemical bonding and interactions between atoms in a compound create new properties that are not simply averages or identical to those of the constituent elements.
4. Consider examples such as sodium (a reactive metal) and chlorine (a poisonous gas) combining to form sodium chloride (table salt), which is a stable, edible compound with properties very different from either element alone.
5. Conclude that the correct statement is that the properties of compounds are usually very different from the properties of the elements that compose them, because chemical combination changes the nature of the substance.