Question

The mass number of an element is 18. It contains 7 electrons. What is the number of protons and neutrons in it ?​

Answer 1

Answer:

Number of protons = number of electrons = 7. Number of neutrons = mass number – number of protons = 18-7 = 11. b. The mass of the atom of an element was found to be equal to or slightly more than the mass of the protons in the atom indicating to presence of an uncharged sub-atomic particle.

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