Final answer:
The notations representing atoms with the same number of protons but a different number of neutrons are isotopes. The correct answer is d) H-3 and He-3, as H-3 (tritium) has one proton and two neutrons, while He-3 (helium) also has one proton but has two neutrons.
Step-by-step explanation:
The notations that represent atoms with the same number of protons but a different number of neutrons are called isotopes. By definition, isotopes of an element have the same atomic number (protons) but different mass numbers due to varying numbers of neutrons. Looking at the options provided in the question, the correct answer is d) H-3 and He-3, as both notations represent elements with the same number of protons but different numbers of neutrons. Specifically, hydrogen (H) and helium (He) both have 1 proton, but H-3 has two neutrons while He-3 has two neutrons.
Let's break down why the other options do not represent isotopes:
- b) S-32 and Sulfur-32 represent the same isotope of sulfur, with the same number of protons and neutrons.
- c) Carbon-14 and Carbon-14 are identical, so they can't represent different isotopes.
- a) Ga-70 and Ge-73 are different elements altogether, with different numbers of protons (gallium and germanium), and thus cannot be isotopes of the same element.