Question:
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Answer:
electrons, protons, neutrons
Structure of the Atom
Q 1.
What do you think would be the observation if the ?-particle scattering experiment is carried out using a foil of a metal other than gold?
Q 2.
Who discovered protons?
Q 3.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Q 4.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 5.
Describe briefly Thomson's model of an atom.
Q 6.
Fill in the blanks :
Anode rays are also called ___________.
Q 7.
What is the relationship between an atom containing 11 protons, 11 electrons and 11 neutrons, and another atom containing 11 protons, 11 electrons and 12 neutrons ?
Q 8.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 9.
What is mass number?
Q 10.
Compare an electron, a proton and a neutron in respect of their relative masses and charges.
Q 11.
Write a short note on Nucleus.
Q 12.
What is the absolute mass and charge of a proton ?
Q 13.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 14.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 15.
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Q 16.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 17.
How many times is a proton heavier than an electron ?
Q 18.
Who discovered electrons?
Q 19.
What is ionization energy?
Q 20.
Fill in the blanks :
Rutherford's scattering experiment is related to to the size of ____________.
Q 21.
If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons present in Na atom?
Q 22.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 23.
What is a neutron ? State its relative mass and charge.
Q 24.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 25.
Fill in the blanks :
Atoms are made up of __________, ___________ and __________.
Q 26.
Fill in the following blanks in respect of an atom of an element :
No.of
protons | No.of
neutrons | Mass number | Atomic
number | No.of
electrons | Valency |
|---|
| 11 | 12 | ........ | ....... | ........ | ......... |
Q 27.
Who discovered neutrons?
Q 28.
What are ?-particles?
Q 29.
Fill in the blanks :
______ are atoms of the same element, which have same number of protons but different mass numbers.
Q 30.
State the location of electrons, protons and neutrons in an atom.
Q 31.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 32.
Fill in the following blanks
Atomic
number | Mass number | Protons | Neutrons | Electrons | Symbol |
|---|
| 10 | 22 | ....... | ........ | ....... | ........ |
Q 33.
Fill in the blanks :
The mass number of an atom is equal to the number of ________ in its nucleus.
Q 34.
What is the electronic configuration of a hydrogen atom
Q 35.
What are the limitations of Rutherford’s model of the atom?
Q 36.
Which part of an atom was discovered by Rutherford's alpha particle scattering experiment ?
Q 37.
Which radioactive isotope is used to determine the activity of thyroid gland ?
Q 38.
Which of the following are isotopes and which are isobars ?
Argon, Deuterium, Calcium, Tritium, Protium
Q 39.
Complete the following table.
| Particle | Electron | Proton | Neutron |
|---|
| (i) Symbol | __ | __ | __ |
| (ii) Nature | __ | __ | __ |
| (iii) Relative Charge | __ | __ | __ |
| (iv) Absolute Charge | __ | __ | __ |
| (v) Relative Mass | __ | __ | __ |
| (vi) Absolute Mass | __ | __ | __ |
Q 40.
Draw a sketch of Bohr’s model of an atom with three shells.
Q 41.
Name the positively charged particle present in the atoms of all the element
Q 42.
How does a proton differ from an electron ?
Q 43.
How does an electron differ from a neutron ?
Q 44.
State one use of radioactive isotopes in medicine.
Q 45.
Name the radioactive isotope which is used in the treatment of cancer.
Q 46.
State one use of radioactive isotopes in industry.
Q 47.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
Q 48.
(a)What are valence electrons ? Where are valence electrons situated in an atom ?
(b)What is the number of valence electrons in the atoms of an element having atomic number 13 ? Name the Valency shell of this atom.
Q 49.
Who discovered nucleus of an atom?
Q 50.
What is the mass of proton as compared to electron?
