Question:
What were the important features of atomic model based on Rutherford's scattering experiment?
Answer:
Main features of atomic model based on Rutherford's scattering experiment:
- Most of the space in the atom is empty.
- Atom consists of a dense small positively charged nucleus which is at the centre of the atom.
- Electrons are distributed in the empty space around the nucleus and move in concentric orbits.
- Volume of nucleus is negligibly small as compared to volume of the atom.
- Charge on Number of electrons is same the total positive charge in the nucleus. Hence atom is electrically neutral.
Structure of the Atom
Q 1.
Who discovered protons?
Q 2.
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 3.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Q 4.
Describe briefly Thomson's model of an atom.
Q 5.
Fill in the blanks :
Anode rays are also called ___________.
Q 6.
Compare an electron, a proton and a neutron in respect of their relative masses and charges.
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.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 9.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 10.
What is the absolute mass and charge of a proton ?
Q 11.
How many times is a proton heavier than an electron ?
Q 12.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 13.
What is mass number?
Q 14.
What is ionization energy?
Q 15.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 16.
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Q 17.
Write a short note on Nucleus.
Q 18.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 19.
What is a neutron ? State its relative mass and charge.
Q 20.
Fill in the blanks :
Atoms are made up of __________, ___________ and __________.
Q 21.
Fill in the blanks :
______ are atoms of the same element, which have same number of protons but different mass numbers.
Q 22.
Who discovered electrons?
Q 23.
Fill in the blanks :
Rutherford's scattering experiment is related to to the size of ____________.
Q 24.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 25.
If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons present in Na atom?
Q 26.
What are ?-particles?
Q 27.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 28.
State the location of electrons, protons and neutrons in an atom.
Q 29.
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 30.
Which part of an atom was discovered by Rutherford's alpha particle scattering experiment ?
Q 31.
How does an electron differ from a neutron ?
Q 32.
Name the radioactive isotope which is used in the treatment of cancer.
Q 33.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 34.
What are the properties of anode rays?
Q 35.
Name the fundamental particle not present in the nucleus of hydrogen atom
Q 36.
Name the shell of an atom which can accommodate a maximum of
(a) 2 electrons (b) 18 electrons
Q 37.
(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 38.
Fill in the blanks :
The fundamental sub-atomic particle called neutron was discovered by ___________.
Q 39.
Fill in the blanks :
The maximum number of electrons that can be accommodated in K-shell are _______.
Q 40.
Name the scientist who discovered electron.
Q 41.
Given that the percentage abundance of the isotope
Ne, is 90% and that of the isotope
Ne, is 10%,calculate the average atomic mass of neon.
Q 42.
Who discovered X-Rays?
Q 43.
Write the limitations of J.J. Thomson's model of an atom.
Q 44.
Draw a sketch of Bohr’s model of an atom with three shells.
Q 45.
What is the absolute mass and charge of an electron ?
Q 46.
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 | Symbol |
|---|
| 11 | 12 | ........ | ....... | ........ | ......... |
Q 47.
The total number of electrons in a nitrogen atom is 7. Find the number of valence electrons in it.
Q 48.
Which radioactive isotope is used to determine the activity of thyroid gland ?
Q 49.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
Q 50.
What are isobars ? Explain with an example.
