An isotope of U-235 has 92 protons in its nucleus. How many neutrons are there in the nucleus of a U-238 isotope?

The iron atom is characterized by an , $"Z=26$. That is every iron nucleus contains $26$ protons, 26, massive, positively charged, nuclear particles, by definition. Of course, the nucleus also...

The , $Z$, of any element, is the number of protons, positively charged nuclear particles, contained in the nucleus. The ($235$) is the sum of the number of protons, AND...

The most important thing to keep in mind here is that are atoms that have the same number of protons inside their nuclei. In other words, an isotope...

And so $""^14C$ necessarily has 6 nuclear protons. And to account for the remaining mass there are 8 $"nucular"$ neutrons. Because the atom is neutral, there must be electrons, in...

are given by the name of the element and the . Here boron-11 means the name of the element is boron and the mass number is 11. We are...

The mass of an atom depends on the number of massive particles. These include (i) the protons, fundamental nuclear particles with unit positive charge, and (ii), the neutrons, fundamental neutral...

And $Z$ defines the identity of the element: $Z=1,H;Z=2,He;..........Z=6,C;........Z=37, Ru...........$ You don't have to remember these numbers, because a Periodic Table will be supplied to you in every test of...

This is called the of the element. To make it up to 13 in carbon-13, you will need 7 neutrons. Stable isotopes are not useful at all in radio-dating,...

Isotope $A$ has 12 nuclear particles. Since there are 6 protons, the element $A$ is $""^12C$, and $B$ is $""^14C$. I can define the identity of the element and its...

$Z$, $"the atomic number"$ of magnesium is 12. This means that there are 12 positively charged nuclear particles. This defines the particle as a magnesium atom. To represent the $""^24Mg$...