What is the difference between atomic number and mass number?
I always confuse these in the periodic table. For Carbon-14 used in radiocarbon dating, which number is 14 and which is 6? How are isotopes related to this?
1 Answer
SJShruti Jain
✓ Accepted
· 13d ago
▲ 5
Atomic number = number of protons (unique per element, determines which element it is). Mass number = protons + neutrons. For Carbon: atomic number = 6 (6 protons, always for carbon). Carbon-12 has 6 protons + 6 neutrons (mass number 12). Carbon-14 has 6 protons + 8 neutrons (mass number 14). Both have 6 electrons in a neutral atom. Isotopes are atoms of the SAME element (same atomic number) but different mass numbers due to different neutron counts. C-14 is radioactive and decays over time, which is why it is used for dating ancient organic material.
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