Are all elements are composed of atoms that cannot be divided?

Answer 1

No. All atoms, except the most abundant isotope of hydrogen, can be divided into the subatomic particles protons, neutrons, and electrons. The most abundant hydrogen isotope does not have neutrons.

Answer 2

No, not all elements are composed of indivisible atoms. Some elements, like helium, have atoms that cannot be further divided, while others, like uranium, have atoms that can be split through nuclear reactions. Elements with atoms that can be divided are known as radioactive elements.