They have the same number of protons (and electrons) - so proton number.
They have a varying number of neutrons - Mass number.
Proton number and Atomic number mean the same things, so Isotopes of an element have the same atomic number.
The atomic number is the same for the isotopes of a chemical element.
The atomic number is the same for the all isotopes of a chemical element.
Isotopes of the same element have different numbers of neutrons in their atomic nuclei. This results in isotopes having slightly different atomic masses while maintaining the same number of protons (which determines the element's identity).
The isotopes of an element have the same number of protons, but different numbers of neutrons.
Atoms of the same element with different atomic masses are known as isotopes. Isotopes differ only by the number of neutrons present in the nucleus of the isotopes. The number of protons is the same for all isotopes of an element (because if there were different numbers of protons, then the atoms would not be of the same element).
Yes, isotopes of an element have the same number of protons but different numbers of neutrons, leading to variations in atomic mass. This is why the atomic mass on the periodic table is often listed as a range for an element.
neutrons
Not a question of why. It just is, isotopes have the same atomic number, (which means that they are all the same element) with different neutron numbers.
Isotopes are alike in that they have the same number of protons (same atomic number), which means they belong to the same element. They also have similar chemical properties due to this shared atomic number. Finally, isotopes can be identified by the element's symbol followed by a hyphen and the mass number.
Isotopes are different forms of the same element which have different numbers of neutrons in their atomic nuclei. A given element is identified by the number of protons in its nucleus; that's its atomic number. Two different isotopes of the same element have the same number of protons, but each has a different number of neutrons in its nucleus. Different isotopes of the same element are chemically the same.
All isotopes of an element have the same number of protons in the atomic nucleus, which is its atomic number on the periodic table. All isotopes of an element contain different numbers of neutrons in their atomic nuclei, which causes the isotopes of an element to vary in mass number (protons + neutrons).
The atomic number is the same for all isotopes.