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प्रश्न
If an atom ‘A’ has atomic number 19 and mass number 39, state –
- Its electronic configuration.
- The number of valence electrons it possesses.
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उत्तर
Atom ‘A’ has mass number A = 39 and atomic number Z = 19 = p
∴ A = Z + n
A = p + n
39 = 19 + n
n = 39 – 19 = 20
But e = p = 19
- A (K, L, M, N)
19 = 2, 8, 8, 1
There will be 2 electrons in K-shell or 1st shell
8 electrons in 2nd shell or L-shell
8 electrons in 3rd shell or M-shell
1 electron in 4th shell or nth-shell - The number of valence electrons i.e. in outer most shell = 1 electron.
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संबंधित प्रश्न
Which of the following are isoelectronic species i.e., those having the same number of electrons?
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Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.
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Atomic no. = 1
Mass no. = 1
Are isotopes atoms of the same element or different elements.
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
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What is common salt? Name the elements present in it. Write the formula of common salt. What are the atomic number and the mass number of the elements? Write the ions in the compound.
Explain the following terms.
- Proton
- Electron
- Neutron.
If an atom has 6 electrons in its outermost shell, it is inert.
Ca2+ has completely filled outer shell. Justify your answer.
