Atom Atomic # Mass #

A 100 257
B 101 257
C 101 260
D 102 259

Question

Atom               Atomic #                 Mass #

A                    100                          257
B                     101                         257
C                     101                         260
D                     102                          259

superhelp101 · Answer

The atomic and mass numbers for four different atoms are given below. Which two are isotopes of the same element?

superhelp101 · Answer

A and B
	B and C
	B and D
	C and D

thomaster · Answer

Do you know what isotopes are?

superhelp101 · Answer

yea! i am making sure is the answer B and C?

thomaster · Answer

If you know what isotopes are, it wouldn't be hard figuring it out right? What is the same in isotopes? And what is different between isotopes of the same element?

superhelp101 · Answer

same chemical properties they differ in the nuclear properties

thomaster · Answer

well yea they have the same chemical properties since the electron configuration is the same. but that's not important here.

The difference which is relevant for this question is the fact that isotopes have the same number of protons, and different number of neutrons. The atomic # is the same thing as the number of protons. When the number of neutrons differs, the mass automatically differs too. So as you can see B and C have the same atomic number, but different mass.

superhelp101 · Answer

oh i see. Thank you!

thomaster · Answer

No problemo :)
Good luck with the rest of your questions.

superhelp101 · Answer

thanks