Why do compounds often have chemical properties that are different from the elements that compose them?

• A. Because the atoms in a compound are chemically bonded, resulting in new substances with unique properties.
• B. Because compounds are formed only by physical changes, not chemical changes.
• C. Because the elements lose all their electrons when forming compounds.
• D. Because compounds are always mixtures of elements, so their properties are an average of the elements.

Answer: (A)

Verified step by step guidance

1. Understand that elements are pure substances consisting of only one type of atom, each with its own distinct chemical properties.
2. Recognize that when elements combine chemically, they form compounds through chemical bonds such as ionic or covalent bonds.
3. Know that chemical bonding involves the sharing or transfer of electrons between atoms, which changes the electron arrangement and energy states.
4. Realize that these new arrangements create substances with properties that are different from the individual elements because the atoms interact in new ways.
5. Conclude that compounds have unique chemical and physical properties that are not simply averages of the properties of the elements that compose them.