Question:
What are canal rays?
Answer:
- Canal rays are positively charged radiations due to positive charged sub-atomic particles.
- These are also called anode rays.
- These were discovered by E. Goldstein in 1866.
- Canal rays pass through perforated cathode and then travel towards another cathode in a gas discharge tube.
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.
Compare an electron, a proton and a neutron in respect of their relative masses and charges.
Q 3.
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 4.
Fill in the blanks :
Anode rays are also called ___________.
Q 5.
Describe briefly Thomson's model of an atom.
Q 6.
Who discovered protons?
Q 7.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
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 the absolute mass and charge of a proton ?
Q 10.
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Q 11.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 12.
How many times is a proton heavier than an electron ?
Q 13.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 14.
What is ionization energy?
Q 15.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 16.
What is mass number?
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 :
______ are atoms of the same element, which have same number of protons but different mass numbers.
Q 21.
Fill in the blanks :
Atoms are made up of __________, ___________ and __________.
Q 22.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 23.
What are ?-particles?
Q 24.
Who discovered electrons?
Q 25.
How does an electron differ from a neutron ?
Q 26.
State the location of electrons, protons and neutrons in an atom.
Q 27.
Name the radioactive isotope which is used in the treatment of cancer.
Q 28.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 29.
If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons present in Na atom?
Q 30.
What is Atomic Number? Who coined this term?
Q 31.
Fill in the blanks :
Atomic number is equal to _____________.
Q 32.
What is a proton ? How does it differ from a neutron ?
Q 33.
State one use of radioactive isotopes in medicine.
Q 34.
State one use of radioactive isotopes in industry.
Q 35.
What are isobars ? Explain with an example.
Q 36.
(a) What are radioactive isotopes ? Give two examples of radioactive isotopes.
(b)Give any two uses of radioactive isotopes.
(c)An element Z contains two naturally occurring isotopes
Z and
Z. If the average atomic mass of this element be 35.5 u, calculate the percentage of two isotopes.
Q 37.
What are canal rays?
Q 38.
Fill in the blanks :
The fundamental particle not present in hydrogen atom is __________.
Q 39.
Fill in the blanks :
Rutherford's scattering experiment is related to to the size of ____________.
Q 40.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
Q 41.
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 42.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 43.
What is the maximum number of electrons that can go into the N shell of an atom ?
Q 44.
Fill in the blanks :
________ rays are negatively charged.
Q 45.
What is the maximum number of electrons which can be accommodated in the K shell of an atom
Q 46.
Which shell of an atom can accommodate a maximum of
(a) 8 electrons?
Q 47.
What were the observations of Rutherford's ?-scattering experiment?
Q 48.
Fill in the blanks :
_______ are atoms having the same mass number but different atomic numbers.
Q 49.
(a) Describe the Rutherford's model of an atom. State one drawback of Rutherford's model of the atom.
(b) The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it ? What is the atomic number of the element ?
Q 50.
Fill in the blanks :
__________ electrons are located in the outermost shell of an atom.
