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Course: Bridge Course Class 11th Chemistry > Unit 1

Lesson 2: Structure of an atom

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Atomic and mass number

Google Classroom

Consider an atom of Sodium

(Na)

. It has a mass number of

23

and an atomic number of

11

.

How many electrons, protons and neutrons does it have?

Number of electrons:
Your answer should be
an integer, like $6$ ‍
a simplified proper fraction, like $3 / 5$ ‍
a simplified improper fraction, like $7 / 4$ ‍
a mixed number, like $1 3 / 4$ ‍
an exact decimal, like $0.75$ ‍
a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Number of protons:
Your answer should be
an integer, like $6$ ‍
a simplified proper fraction, like $3 / 5$ ‍
a simplified improper fraction, like $7 / 4$ ‍
a mixed number, like $1 3 / 4$ ‍
an exact decimal, like $0.75$ ‍
a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Number of neutrons:
Your answer should be
an integer, like $6$ ‍
a simplified proper fraction, like $3 / 5$ ‍
a simplified improper fraction, like $7 / 4$ ‍
a mixed number, like $1 3 / 4$ ‍
an exact decimal, like $0.75$ ‍
a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍