An element is a pure substance that consists of only one type of what?

An element is a pure substance that consists of only one type of what?

• A. Molecule
• B. Ion
• C. Compound
• D. Atom

Answer: (D)

An element is a pure substance that contains only one type of atom. This means every particle in the substance is an atom of the same element, whether the atoms are shown as isolated units or as molecules made entirely of that same atom (like O2, which is two oxygen atoms bonded together). The key idea is that only one kind of atom is present. A molecule is simply a group of atoms bonded together and can be made of different elements or the same element, but the defining feature of an element is the single type of atom. An ion is a charged particle, and a compound is made from two or more different elements chemically combined, which is why they don’t fit the definition of an element.

An element is a pure substance that contains only one type of atom. This means every particle in the substance is an atom of the same element, whether the atoms are shown as isolated units or as molecules made entirely of that same atom (like O2, which is two oxygen atoms bonded together). The key idea is that only one kind of atom is present. A molecule is simply a group of atoms bonded together and can be made of different elements or the same element, but the defining feature of an element is the single type of atom. An ion is a charged particle, and a compound is made from two or more different elements chemically combined, which is why they don’t fit the definition of an element.