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प्रश्न
The diagram represents an isotope of hydrogen [H]. Answer the following:
Atomic no. = 1
Mass no. = 1
If an isotope of ‘H’ has mass no. = 3, how many neutrons does it have.
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उत्तर
Two neutrons. .........[∵ A = P + n]
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संबंधित प्रश्न
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Atomic theory of matter was given by ..........................
Fill in the following blanks :
| Atomic Number | Mass Number | Protons | Neutrons | Electrons | Symbol |
| 10 | 22 | _________ | _________ | _________ | _________ |
The mass number of an element is 18. It contains 7 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
An element A atomic number 7 mass numbers 14
B electronic configuration 2,8,8
C electrons 13, neutrons 14
D Protons 18 neutrons 22
E Electronic configuration 2,8,8,1
State Valency of each element
An element A atomic number 7 mass numbers 14
B electronic configuration 2,8,8
C electrons 13, neutrons 14
D Protons 18 neutrons 22
E Electronic configuration 2,8,8,1
State (i) Valency of each element (ii) which one is a metal (iii) which is non-metal (iv) which is an inert gas
If an atom ‘A’ has atomic number 19 and mass number 39, state –
- Its electronic configuration.
- The number of valence electrons it possesses.
‘Valency is the number of hydrogen atoms which can combine with [or displace] one atom of the element [or radical] forming a compound’. With reference to the above definition of valency, state the valency of chlorine in hydrogen chloride, giving reasons.
Match the statements in List I with the correct answer from List II.
| List I | List II |
| 1. Mass number of an atom is the number of protons and | A: Electron |
| 2. The sub-atomic particle with a negligible mass. | B: Argon |
| 3. An atom having stable electronic configuration. | C: Nitrogen |
| 4. A molecule formed by sharing of electrons [covalency] | D: Sodium |
| 5. A metallic atom having unstable electronic configuration. | E: Neutrons |
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Lithium [At. no. = 3, Mass no. = 7]
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Sodium [At. no. = 11, Mass no. = 23]
The atomic number of an element is 9, it has 10 neutrons. Find the element from the periodic table. What will be its mass number?
