Are the number of protons in an element the same for all neutral atoms of that same element?

Answer 1

No. There are several very common cases in which the number of neutrons differs from the number of protons. For early elements (the lighter ones), the proton to neutron ratio is generally 1 to 1. For example, the common hydrogen atom always has 1 proton, and usually 1 neutron. Larger elements, such as uranium, have a larger ratio. If you have ever seen, uranium is often referred to as uranium 238, the key particle in the atomic bomb. Uranium has 92 protons, meaning the difference in mass is accounted for by 146 neutrons. So the neutron to proton ratio in this case is about 1.6.

The reason that the ratio differs along the Periodic Table can be explained by two forces. The first is electromagnetism. You are probably familiar with this. Life particles (such as 2 protons) repel while opposite particle (such as proton and electron) attract. But remember that electrons orbit around the nucleus of an atom. The nucleus itself consists of protons and neutrons. Neutrons don't seem to matter as they are electrically neutral, but how are protons able to sit by each other so tightly packed if a powerful repulsive force exists between them? The answer to that lies in a different force that is strong enough to overcome their repulsiveness at extremely close distances. This force is actually simply called the strong force or sometimes, the strong nuclear force. This force is an attraction between protons and protons, neutrons and neutrons, and even protons and neutrons!

I'm not sure how well this force is understood, but we certainly know it's there. Otherwise, it would be impossible for the elements of the periodic table to even exist due to the electromagnetic repulsion of like particles! Now as we get to bigger and bigger elements along the periodic table, there are more protons packed together in a tightly spaced nucleus of a given element. This means that the electromagnetic repulsive force is dramatically increasing simply because there are more particles to repel each other. More neutrons, then, are needed to maintain a form of equilibrium, something strong enough to bind the nucleus in place. Therefore, the ratio increases.

One last note: I stated that the early elements held a one to one proton to neutron ratio in general, leaving the implication that it does not necessarily have to be one to one. This would be correct if you thought that. The hydrogen atom actually has two other known isotopes (different number of neutrons then usual). Hydrogen can have one proton and two neutrons. This compound is known as deuterium, and is part of the cause for "hard water". However, deuterium is a more unstable form and does not exist as much. Hydrogen can also exist with three neutrons, and this particle is known as tritium. It is highly radioactive due to the substantial instability that it holds. A particle of such small size is not "designed" to hold onto so many neutrons because it doesn't really need more than 1 to account for the one proton. Because of such a high instability, tritium very rarely exists at all.

Hope this helped! :)

Answer 2

The number of protons is what defines the element. It is always the same regardless of the charge or isotope for each element.

Answer 3

Yes your atomic number and the number of protons will always be the same!

Answer 4

not always, but the number of protons are always the same, if not it's another substance. Elements with various numbers of neutrons are known as radioactive.

he means isotope.

Answer 5

no

Answer 6

No