What is an element?

What is an element?

• A. A pure substance made of only one kind of atom
• B. A table of elements on the periodic table
• C. A subatomic particle with a positive charge
• D. The center of an atom

Answer: (A)

An element is a pure substance made of only one kind of atom. This means every atom in the element has the same number of protons, giving it a specific identity such as hydrogen or oxygen. Elements can exist as individual atoms or as molecules made of the same kind of atom (for example, O2), but they are still composed of only one type of atom. They cannot be broken down into simpler substances by chemical means. The other descriptions refer to a chart of elements (the periodic table), a subatomic particle with a positive charge (a proton), and the center of an atom (the nucleus), which are different concepts.

An element is a pure substance made of only one kind of atom. This means every atom in the element has the same number of protons, giving it a specific identity such as hydrogen or oxygen. Elements can exist as individual atoms or as molecules made of the same kind of atom (for example, O2), but they are still composed of only one type of atom. They cannot be broken down into simpler substances by chemical means. The other descriptions refer to a chart of elements (the periodic table), a subatomic particle with a positive charge (a proton), and the center of an atom (the nucleus), which are different concepts.