Two isotopes of carbon are ¹²₆𝐶 and ¹⁴₆𝐶 The electronic configuration of ¹²₆𝐶 is 2, 4. The electronic configuration of ¹⁴₆𝐶 is 2, 4. [Isotopes have same electronic configuration] ⁴⁰₂₉𝐶𝑎 and ⁴⁰₁₈𝐴𝑟 are a pair of isobars The electronic configuration of ⁴⁰₂₉𝐶𝑎 is 2, 8, 8, 2 The electronic configurationRead more
Two isotopes of carbon are ¹²₆𝐶 and ¹⁴₆𝐶
The electronic configuration of ¹²₆𝐶 is 2, 4.
The electronic configuration of ¹⁴₆𝐶 is 2, 4.
[Isotopes have same electronic configuration]
⁴⁰₂₉𝐶𝑎 and ⁴⁰₁₈𝐴𝑟 are a pair of isobars
The electronic configuration of ⁴⁰₂₉𝐶𝑎 is 2, 8, 8, 2
The electronic configuration of ⁴⁰₁₈𝐴𝑟 is 2, 8, 8.
[Isobars have different electronic configuration]
Symbol Proton Neutron Electron H 1 0 1 D 1 1 1 For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/
Mass number of oxygen = Number of protons + Number of neutrons = 8 + 8 = 16 Mass number of sulphur = Number of protons + Number of neutrons = 16 +16 = 32 For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/
Mass number of oxygen = Number of protons + Number of neutrons
= 8 + 8
= 16
Mass number of sulphur = Number of protons + Number of neutrons
= 16 +16
= 32
(i) The atomic number is equal to the number of protons. Therefore, the atomic number of the atom is 8. (ii) Since the number of both electrons and protons is equal, therefore, the charge on the atom is 0. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/scienRead more
(i) The atomic number is equal to the number of protons. Therefore, the atomic number of
the atom is 8.
(ii) Since the number of both electrons and protons is equal, therefore, the charge on the
atom is 0.
If the number of electrons in the outermost shell of the atom of an element is less than or equal to 4, then the valency of the element is equal to the number of electrons in the outermost shell. On the other hand, if the number of electrons in the outermost shell of the atom of an element is greateRead more
If the number of electrons in the outermost shell of the atom of an element is less than or equal to
4, then the valency of the element is equal to the number of electrons in the outermost shell.
On the other hand, if the number of electrons in the outermost shell of the atom of an element is greater than 4, then the valency of that element is determined by subtracting the number of electrons in the outermost shell from 8.
The distribution of electrons in chlorine, sulphur, and magnesium atoms are 2, 8, 7; 2, 8, 6 and 2, 8, 2 respectively. Therefore, the number of electrons in the outer most shell of chlorine, sulphur, and magnesium atoms are 7, 6, and 2 respectively.
Thus,
The valency of chlorine = 8 −7 = 1
The valency of sulphur = 8 − 6 = 2
The valency of magnesium = 2
The maximum number of electrons that can occupy K and L-shells of an atom are 2 and 8 respectively. Therefore, if K and L-shells of an atom are full, then the total number of electrons in the atom would be (2 + 8) = 10 electrons. For more answers visit to website: https://www.tiwariacademy.com/ncertRead more
The maximum number of electrons that can occupy K and L-shells of an atom are 2 and 8
respectively. Therefore, if K and L-shells of an atom are full, then the total number of electrons in
the atom would be (2 + 8) = 10 electrons.
The total number of electrons in a carbon atom is 6. The distribution of electrons in carbon atom is given by: First orbit or K-shell = 2 electrons Second orbit or L-shell = 4 electrons Or, we can write the distribution of electrons in a carbon atom as 2, 4. The total number of electrons in a sodiumRead more
The total number of electrons in a carbon atom is 6. The distribution of electrons in carbon atom
is given by:
First orbit or K-shell = 2 electrons
Second orbit or L-shell = 4 electrons
Or,
we can write the distribution of electrons in a carbon atom as 2, 4.
The total number of electrons in a sodium atom is 11. The distribution of electrons in sodium atom
is given by:
First orbit or K-shell = 2 electrons
Second orbit or L-shell = 8 electrons
Third orbit or M-shell = 1 electron
Or,
we can write distribution of electrons in a sodium atom as 2, 8, 1.
Helium atom has two neutrons. The mass of an atom is the sum of the masses of protons and neutrons present in its nucleus. Since helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u. Then, the remaining mass (4 − 2) u = 2 u is contributed by 2u /1u = 2 neutrons. For moRead more
Helium atom has two neutrons. The mass of an atom is the sum of the masses of protons and
neutrons present in its nucleus.
Since helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u.
Then, the remaining mass (4 − 2) u = 2 u is contributed by 2u /1u = 2 neutrons.
The three sub-atomic particles of an atom are: (i) Protons (ii) Electrons, and (iii) Neutrons For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/
The three sub-atomic particles of an atom are:
(i) Protons
(ii) Electrons, and
(iii) Neutrons
If the α-scattering experiment is carried out using a foil of a metal rather than gold, there would be no change in the observation. In the α-scattering experiment, a gold foil was taken because gold is malleable and a thin foil of gold can be easily made. It is difficult to make such foils from othRead more
If the α-scattering experiment is carried out using a foil of a metal rather than gold, there would be no change in the observation. In the α-scattering experiment, a gold foil was taken because gold is malleable and a thin foil of gold can be easily made. It is difficult to make such foils from other metals.
Write the electronic configuration of any one pair of isotopes and isobars.
Two isotopes of carbon are ¹²₆𝐶 and ¹⁴₆𝐶 The electronic configuration of ¹²₆𝐶 is 2, 4. The electronic configuration of ¹⁴₆𝐶 is 2, 4. [Isotopes have same electronic configuration] ⁴⁰₂₉𝐶𝑎 and ⁴⁰₁₈𝐴𝑟 are a pair of isobars The electronic configuration of ⁴⁰₂₉𝐶𝑎 is 2, 8, 8, 2 The electronic configurationRead more
Two isotopes of carbon are ¹²₆𝐶 and ¹⁴₆𝐶
The electronic configuration of ¹²₆𝐶 is 2, 4.
The electronic configuration of ¹⁴₆𝐶 is 2, 4.
[Isotopes have same electronic configuration]
⁴⁰₂₉𝐶𝑎 and ⁴⁰₁₈𝐴𝑟 are a pair of isobars
The electronic configuration of ⁴⁰₂₉𝐶𝑎 is 2, 8, 8, 2
The electronic configuration of ⁴⁰₁₈𝐴𝑟 is 2, 8, 8.
[Isobars have different electronic configuration]
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For the symbol H,D and T tabulate three sub-atomic particles found in each of them.
Symbol Proton Neutron Electron H 1 0 1 D 1 1 1 For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/
Symbol Proton Neutron Electron
H 1 0 1
D 1 1 1
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With the help of Table 4.1, find out the mass number of oxygen and Sulphur atom.
Mass number of oxygen = Number of protons + Number of neutrons = 8 + 8 = 16 Mass number of sulphur = Number of protons + Number of neutrons = 16 +16 = 32 For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/
Mass number of oxygen = Number of protons + Number of neutrons
= 8 + 8
= 16
Mass number of sulphur = Number of protons + Number of neutrons
= 16 +16
= 32
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If number of electrons in an atom is 8 and number of protons is also 8, then (i) what is the atomic number of the atom? and (ii) what is the charge on the atom?
(i) The atomic number is equal to the number of protons. Therefore, the atomic number of the atom is 8. (ii) Since the number of both electrons and protons is equal, therefore, the charge on the atom is 0. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/scienRead more
(i) The atomic number is equal to the number of protons. Therefore, the atomic number of
the atom is 8.
(ii) Since the number of both electrons and protons is equal, therefore, the charge on the
atom is 0.
For more answers visit to website:
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How will you find the valency of chlorine, Sulphur and magnesium?
If the number of electrons in the outermost shell of the atom of an element is less than or equal to 4, then the valency of the element is equal to the number of electrons in the outermost shell. On the other hand, if the number of electrons in the outermost shell of the atom of an element is greateRead more
If the number of electrons in the outermost shell of the atom of an element is less than or equal to
4, then the valency of the element is equal to the number of electrons in the outermost shell.
On the other hand, if the number of electrons in the outermost shell of the atom of an element is greater than 4, then the valency of that element is determined by subtracting the number of electrons in the outermost shell from 8.
The distribution of electrons in chlorine, sulphur, and magnesium atoms are 2, 8, 7; 2, 8, 6 and 2, 8, 2 respectively. Therefore, the number of electrons in the outer most shell of chlorine, sulphur, and magnesium atoms are 7, 6, and 2 respectively.
Thus,
The valency of chlorine = 8 −7 = 1
The valency of sulphur = 8 − 6 = 2
The valency of magnesium = 2
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If K and L shells of an atom are full, then what would be the total number of electrons in the atom?
The maximum number of electrons that can occupy K and L-shells of an atom are 2 and 8 respectively. Therefore, if K and L-shells of an atom are full, then the total number of electrons in the atom would be (2 + 8) = 10 electrons. For more answers visit to website: https://www.tiwariacademy.com/ncertRead more
The maximum number of electrons that can occupy K and L-shells of an atom are 2 and 8
respectively. Therefore, if K and L-shells of an atom are full, then the total number of electrons in
the atom would be (2 + 8) = 10 electrons.
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Write the distribution of electrons in carbon and sodium atoms.
The total number of electrons in a carbon atom is 6. The distribution of electrons in carbon atom is given by: First orbit or K-shell = 2 electrons Second orbit or L-shell = 4 electrons Or, we can write the distribution of electrons in a carbon atom as 2, 4. The total number of electrons in a sodiumRead more
The total number of electrons in a carbon atom is 6. The distribution of electrons in carbon atom
is given by:
First orbit or K-shell = 2 electrons
Second orbit or L-shell = 4 electrons
Or,
we can write the distribution of electrons in a carbon atom as 2, 4.
The total number of electrons in a sodium atom is 11. The distribution of electrons in sodium atom
is given by:
First orbit or K-shell = 2 electrons
Second orbit or L-shell = 8 electrons
Third orbit or M-shell = 1 electron
Or,
we can write distribution of electrons in a sodium atom as 2, 8, 1.
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Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
Helium atom has two neutrons. The mass of an atom is the sum of the masses of protons and neutrons present in its nucleus. Since helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u. Then, the remaining mass (4 − 2) u = 2 u is contributed by 2u /1u = 2 neutrons. For moRead more
Helium atom has two neutrons. The mass of an atom is the sum of the masses of protons and
neutrons present in its nucleus.
Since helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u.
Then, the remaining mass (4 − 2) u = 2 u is contributed by 2u /1u = 2 neutrons.
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Name the three sub-atomic particles of an atom.
The three sub-atomic particles of an atom are: (i) Protons (ii) Electrons, and (iii) Neutrons For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/
The three sub-atomic particles of an atom are:
(i) Protons
(ii) Electrons, and
(iii) Neutrons
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What do you think would be the observation if the α-particle scattering experiment is carried out using a foil of a metal other than gold?
If the α-scattering experiment is carried out using a foil of a metal rather than gold, there would be no change in the observation. In the α-scattering experiment, a gold foil was taken because gold is malleable and a thin foil of gold can be easily made. It is difficult to make such foils from othRead more
If the α-scattering experiment is carried out using a foil of a metal rather than gold, there would be no change in the observation. In the α-scattering experiment, a gold foil was taken because gold is malleable and a thin foil of gold can be easily made. It is difficult to make such foils from other metals.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-4/