which is the correct symbol for an isotope of helium with 2 neutrons? a 1he2 b 3he c 2he d 4he
which is the correct symbol for an isotope of helium with 2 neutrons? a 1he2 b 3he c 2he d 4he
Answer
Brief Explanations:
Helium has an atomic number (number of protons) of 2. The mass - number of an isotope is the sum of protons and neutrons. Given 2 neutrons and 2 protons for helium, the mass - number is 4. The symbol for an isotope is written as $^{A}_{Z}X$, where $A$ is the mass - number and $Z$ is the atomic number. For helium ($He$) with atomic number 2 and mass - number 4, the symbol is $^{4}He$.
Answer:
D. $^{4}He$