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प्रश्न
Differentiate mass number from atomic number.
उत्तर
| Sr. No. | Atomic number | Mass number |
| 1. | The number of electrons or protons in an atom is called atomic number of that atom. | The number of protons and neutrons present is its nucleus is called mass number of that atom. |
| 2. | It is represented by the letter Z | It is represented by the letter ‘A’. |
| 3. | Example: Helium (He) has 2 protons and two electrons hence its atomic number will be 2. | Example: Sodium (Na) has 11 protons and 12 Neutrons hence its mass number A= 11 + 12 = 23 |
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| Atomic Number | Mass Number | Number of Neutrons | Number of Protons | Number of Electrons | Name of the Element |
| 9 | ______ | 10 | ______ | ______ | ______ |
| 16 | ______ | 16 | ______ | ______ | ______ |
| ______ | 24 | ______ | ______ | 12 | Magnesium |
| ______ | 2 | ______ | 1 | ______ | ______ |
| ______ | 1 | 0 | 1 | 1 | ______ |
‘A’ is denoted by ______.
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