Uranium-235 and uranium-238 sit in the same ore. Both are uranium through and through, with 92 protons in every nucleus. The names differ because one number differs, and the last lesson's sort says which number it must be.
You can already sort a changed nucleus: the proton count alone fixes the element, so a changed neutron count leaves the element the same. This lesson names the versions that sort produces, and decodes names like uranium-235.
Atoms whose nuclei hold the same number of protons but different numbers of neutrons are versions of the same element.
Uranium-235 and uranium-238 are both uranium, with 92 protons each.
Uranium-238 has three more neutrons than uranium-235; the two are isotopes of uranium.
The number in a name like uranium-235 gives the nucleus's total count of protons plus neutrons.
For uranium-235, the 92 protons and 143 neutrons total 235.
Subtract the proton count from the name's number, and the neutron count is what remains.
Every element's isotopes are named the same way: carbon-12, carbon-14, helium-4.
A nucleus holds 26 protons and 30 neutrons, and a nucleus with 26 protons is iron. What is this isotope called?
The name's number is the total count of protons plus neutrons.
26 protons plus 30 neutrons makes a total of 56.
The element is iron, because the proton count is 26.
The isotope is called iron-56.
Uranium-235 and uranium-238 both have 92 protons. How many more neutrons does uranium-238 have?
For uranium-235, the neutron count is 235 minus 92, which is 143.
For uranium-238, the neutron count is 238 minus 92, which is 146.
146 minus 143 is 3.
Uranium-238 has three more neutrons than uranium-235.
Uranium-235 and uranium-238 are both uranium. In what way do their nuclei differ?
What does the 235 in the name uranium-235 count?
Caspian says: 'Two atoms with the same number of protons but different numbers of neutrons are isotopes of the same element.' Is Caspian correct?
A nucleus holds 17 protons and 18 neutrons, and a nucleus with 17 protons is chlorine. Which name is right?
Carbon-12 and carbon-14 are both carbon, with 6 protons each. How many neutrons does a carbon-14 nucleus hold?
What do we call atoms whose nuclei hold the same number of protons but different numbers of neutrons?