Final answer:
An element is the simplest, most fundamental unit of composition of matter. It cannot be broken down into simpler substances by ordinary chemical means and consists of only one type of atom.
Step-by-step explanation:
An element is the simplest type of chemical substance and the most fundamental unit of composition of matter. It cannot be broken down into simpler substances by ordinary chemical means. An element consists of only one type of atom, which has a mass that is characteristic of the element and is the same for all atoms of that element.
Examples of elements include iron, carbon, and gold. An element is the simplest, most fundamental unit of composition of matter. It cannot be broken down into simpler substances by ordinary chemical means and consists of only one type of atom.