Final answer:
When elements chemically combine, they form compounds with properties that are different from the individual contributing elements. Compounds have a definite composition and may exhibit unique physical and chemical characteristics not found in the separate elements.
Step-by-step explanation:
When elements are chemically combined, they form a new substance known as a compound, which has different properties from the elements that constitute it. The properties of a compound do not resemble the properties of its component elements, whether considered individually or together. The process of forming compounds can significantly alter the physical and chemical characteristics of the elements involved. For example, sodium is a soft, metallic solid, and chlorine is a yellow-green gas, but when they combine, they form sodium chloride (table salt), which is a white, crystalline solid. Therefore, the correct answer is (d) The compound formed has different properties than either of the elements.