Do all atoms of the same element contain the same number of protons? Explain.

No, not all atoms of the same element contain the same number of protons. The number of protons in the nucleus of an atom is what defines the element itself. For example, all carbon atoms have 6 protons. However, all atoms of the same element do indeed have the same number of protons. This is a fundamental characteristic of elements: the number of protons, also known as the atomic number, is unique to each element and does not change.

What can vary among atoms of the same element is the number of neutrons, which leads to the formation of isotopes. Isotopes are atoms of the same element that have different numbers of neutrons. For example, carbon-12 and carbon-14 are both isotopes of carbon, with 6 protons each, but with 6 and 8 neutrons, respectively.