Question

In the symbol He, the superscript 4 is the _________________ for helium, and the subscript 2 is the ___________________ for helium.


All of the answers I've looked up have been wrong. I believe I've found the answer.
Look on page 293 of your textbooks.
The textbook says, "The common symbol for an alpha particle is 4/2 He. The subscript is the atomic number (the number of protons). The super- script is the mass number (the sum of the numbers of protons and neutrons)."

Therefore the answer should be: Super-script 4 is the mass number, Subscript 2 is the atomic number
 

Answer 1

Look on page 293 of your textbooks to fact check.
The symbol for an alpha particle is 4/2 He.
The super- script (4) is the mass number (the sum of the numbers of protons and neutrons).
The subscript (2) is the atomic number (the number of protons).

Therefore the answer should be: Super-script 4 is the mass number, Subscript 2 is the atomic number