Question:
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?
Answer:
Gold foil was chosen because gold is malleable and the foil can be made as thick as 1000 atoms. Foils made by other metals if are thicker than the gold foil, the scattering result may not be exactly the same. It may be due to absorption of electrons by thicker foil and we could not reach the same inference. If the foil is as thick as the gold foil, inference would be the same.
Structure of the Atom
Q 1.
Compare an electron, a proton and a neutron in respect of their relative masses and charges.
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 :
Anode rays are also called ___________.
Q 4.
Who discovered protons?
Q 5.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Q 6.
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 7.
What is the absolute mass and charge of a proton ?
Q 8.
Describe briefly Thomson's model of an atom.
Q 9.
How many times is a proton heavier than an electron ?
Q 10.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 11.
What is mass number?
Q 12.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 13.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 14.
What is ionization energy?
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.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 17.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 18.
What is a neutron ? State its relative mass and charge.
Q 19.
Write a short note on Nucleus.
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.
Name the radioactive isotope which is used in the treatment of cancer.
Q 23.
Fill in the blanks :
Atomic number is equal to _____________.
Q 24.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 25.
What is the maximum number of electrons that can go into the N shell of an atom ?
Q 26.
Fill in the blanks :
The fundamental particle not present in hydrogen atom is __________.
Q 27.
Which shell of an atom can accommodate a maximum of
(a) 8 electrons?
Q 28.
(a) Describe Bohr's model of the atom. How did Neils Bohr explain the stability of atom ?
(b) An element has an atomic number of 11 and its mass number is 23. What is the arrangement of electrons in the shells ? State nuclear composition of an atom of the element.
Q 29.
State one use of radioactive isotopes in medicine.
Q 30.
State one use of radioactive isotopes in industry.
Q 31.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
Q 32.
Fill in the blanks :
Nucleons are __________ and ___________.
Q 33.
What do you understand by the term 'electronic configuration' of an element ? Write down the electron configuration of oxygen (At. No. = 8).
Q 34.
(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 35.
Name the fundamental particle not present in the nucleus of hydrogen atom
Q 36.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 37.
Fill in the blanks :
________ rays are negatively charged.
Q 38.
What is the maximum number of electrons which can be accommodated in the K shell of an atom
Q 39.
Name the particles which actually determine the mass of an atom.
Q 40.
What is a proton ? How does it differ from a neutron ?
Q 41.
How does an electron differ from a neutron ?
Q 42.
State the location of electrons, protons and neutrons in an atom.
Q 43.
Fill in the following blanks
Atomic
number | Mass number | Protons | Neutrons | Electrons | Symbol |
|---|
| 10 | 22 | ....... | ........ | ....... | ........ |
Q 44.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 45.
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 46.
What valencies will be shown by the elements A, B, C, D and E having atomic numbers 2, 4, 8, 10, and 13 respectively.
Q 47.
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 48.
Who discovered neutrons?
Q 49.
What are canal rays?
Q 50.
What are the properties of anode rays?
