An atom has atomic number 11 and mass number 23. how many electrons does the atom have?

23
22
12
11

11

Explanation:

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons

Hence, number of electrons is equal to the atomic number which is 11.

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