Question:
Who discovered neutrons?
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.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 11.
What is mass number?
Q 12.
What is ionization energy?
Q 13.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 14.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 15.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 16.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 17.
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Q 18.
Write a short note on Nucleus.
Q 19.
What is a neutron ? State its relative mass and charge.
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.
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.
What is the maximum number of electrons that can go into the N shell of an atom ?
Q 25.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 26.
Fill in the blanks :
Co-60 a radio isotope is used in treatment of __________.
Q 27.
Fill in the blanks in the following statements :
(a)The number of protons in the nucleus of an atom is called
(b)The total number of protons and neutrons in the nucleus of an atom is called its.........
(c) An atom has atomic mass number 23 and atomic number 11. The atom has..........electrons.
(d) An atom of an element has 11 protons,11 electrons and 12 neutrons. The atomic mass of the atom is........
(e)If the nucleus of an atom has atomic number 17, mass number 37 and there are 17 electrons outside the nucleus, the number of neutrons in it is.........
(f) Almost all the mass of an atom is concentrated in a small region of space called the.......
(g)Cathode rays are a beam of fast moving.......
(h) The anode rays obtained from hydrogen gas consist of particles called.......
(I)The maximum number of electrons that can be accommodated in L shell is.......
(j) The maximum number of electrons that can go into the M shell is.........
(k)The subatomic particle not present in a hydrogen atom is.....
(L) The electron has................charge, the proton has..........charge, and the neutron has............charge.?
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.
Which shell of an atom can accommodate a maximum of
(a) 8 electrons?
Q 30.
State one use of radioactive isotopes in medicine.
Q 31.
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 32.
What are the properties of anode rays?
Q 33.
State the location of electrons, protons and neutrons in an atom.
Q 34.
Fill in the following blanks
Atomic
number | Mass number | Protons | Neutrons | Electrons | Symbol |
|---|
| 10 | 22 | ....... | ........ | ....... | ........ |
Q 35.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 36.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
Q 37.
Fill in the blanks :
The fundamental particle not present in hydrogen atom is __________.
Q 38.
Fill in the blanks :
Nucleons are __________ and ___________.
Q 39.
State whether the following statements are true or false :
(a)Thomson proposed that the nucleus of an atom contains protons and neutrons.
(b) The cathode rays obtained from all the gases consist of negatively charged particles called electrons.
(c)The anode rays obtained from all the gases onsist of positively charged particles called protons
Q 40.
Which part of an atom was discovered by Rutherford's alpha particle scattering experiment ?
Q 41.
State one use of radioactive isotopes in industry.
Q 42.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 43.
Fill in the blanks :
________ rays are negatively charged.
Q 44.
What do you understand by the term 'electronic configuration' of an element ? Write down the electron configuration of oxygen (At. No. = 8).
Q 45.
An element has an atomic number 12. How many electrons will be present in the K, L and M energy shell of its atom ?
Q 46.
(a) What is the nucleus of an atom and what is the nature of charge on it ?
(b) Name the scientist who discovered the nucleus of atom.
Q 47.
How does an electron differ from a neutron ?
Q 48.
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 49.
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 50.
What are isobars ? Explain with an example.
