An atom of carbon has 6 protons. Its mass number is 1 2. How many neutrons are present in an atom of carbon ?

The number of neutrons in an atom is determined by the relationship between its mass number and its atomic number. The mass number (A) is defined as the sum of the total number of protons and neutrons present in the nucleus of an atom [3]. The number of protons in the nucleus determines the element's atomic number (Z) [1]. To calculate the number of neutrons, one must subtract the number of protons (atomic number) from the mass number [3]. In this specific case, the carbon atom has 6 protons and a mass number of 12. Applying the formula (Mass Number - Protons = Neutrons), we get 12 - 6 = 6 neutrons [2]. This specific isotope is known as Carbon-12, which is the most common form of carbon [1].

Sources

1. [3] https://www.khanacademy.org/science/biology/history-of-life-on-earth/radiometric-dating/a/atomic-number-atomic-mass-and-isotopes-article
2. [1] https://www.energy.gov/science/doe-explainsisotopes
3. [2] https://remm.hhs.gov/atomicshorthand.htm