Multiple Choice
How many neutrons are in an atom of magnesium-25 ()? (Atomic number of Mg is 12.)
3
views
4. Atoms and Elements
Isotopes
Struggling with Introduction to Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which pair of nuclide notations represent isotopes of the same element?
A
and
B
and
C
and
D
and
Verified step by step guidance1
Recall that isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. This means isotopes have the same atomic number but different mass numbers.
Identify the element symbol in each nuclide notation. The element symbol tells you the number of protons (atomic number) because each element has a unique atomic number.
Compare the element symbols of each pair to see if they are the same. If the symbols differ, the nuclides are different elements and cannot be isotopes.
For pairs with the same element symbol, check the superscript numbers (mass numbers). Different mass numbers with the same element symbol indicate isotopes.
Conclude that the pair with the same element symbol but different mass numbers represents isotopes of the same element.
Related Videos
Related Practice
