How do two isotopes of the same element compare with each other?
A.They have the same number of protons but a different number of electrons.
B.They have the same mass number but a different number of protons.
C.They have the same mass number but a different number of neutrons.
D.They have the same number of protons but a different number of neutrons.
(D)
in any atom the protons always equal the electrons, which is the atomic number.
The only thing left that can vary is the number of neutrons, which gives a different mass number (protons+neutrons)
To determine how two isotopes of the same element compare with each other, we need to understand what isotopes are. Isotopes are atoms of the same element that have different numbers of neutrons.
Now, let's break down the given options to find the correct answer:
A. "They have the same number of protons but a different number of electrons." The number of protons determines the element and its atomic number, while the number of electrons determines the atom's charge. Since we are comparing isotopes of the same element, they will have the same number of protons. However, the number of electrons is not related to isotopes. Therefore, option A is incorrect.
B. "They have the same mass number but a different number of protons." The mass number represents the total number of protons and neutrons in an atom. It is not related to isotopes. Therefore, option B is incorrect.
C. "They have the same mass number but a different number of neutrons." This option correctly describes isotopes. Isotopes have the same mass number, which is the sum of protons and neutrons, but they differ in the number of neutrons. Therefore, option C is the correct answer.
D. "They have the same number of protons but a different number of neutrons." This option incorrectly states that the number of protons is the same, which is true for isotopes but not for all elements. Therefore, option D is incorrect.
In conclusion, the correct answer is C. Isotopes have the same mass number but a different number of neutrons.