Question:
Fill in the blanks :
The total number of protons and neutrons in the nucleus of an atom is called its __________.
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.
Describe briefly Thomson's model of an atom.
Q 3.
Write a short note on Nucleus.
Q 4.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Q 5.
Who discovered protons?
Q 6.
If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons present in Na atom?
Q 7.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 8.
Fill in the blanks :
Rutherford's scattering experiment is related to to the size of ____________.
Q 9.
Who discovered electrons?
Q 10.
How many times is a proton heavier than an electron ?
Q 11.
Compare an electron, a proton and a neutron in respect of their relative masses and charges.
Q 12.
What is mass number?
Q 13.
Fill in the blanks :
Anode rays are also called ___________.
Q 14.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 15.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 16.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 17.
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 18.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 19.
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Q 20.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 21.
What is ionization energy?
Q 22.
What is the absolute mass and charge of a proton ?
Q 23.
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 24.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 25.
Fill in the following blanks
Atomic
number | Mass number | Protons | Neutrons | Electrons | Symbol |
|---|
| 10 | 22 | ....... | ........ | ....... | ........ |
Q 26.
What is a proton ? How does it differ from a neutron ?
Q 27.
Name the scientist who discovered electron.
Q 28.
Who discovered nucleus of an atom?
Q 29.
Name the shell of an atom which can accommodate a maximum of
(a) 2 electrons (b) 18 electrons
Q 30.
What are ?-particles?
Q 31.
Fill in the blanks :
_______ are atoms having the same mass number but different atomic numbers.
Q 32.
What is the absolute mass and charge of an electron ?
Q 33.
(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 34.
State one use of radioactive isotopes in medicine.
Q 35.
What name is given to the pair of atoms such as
N and
N ?
Q 36.
What were the observations of Rutherford's ?-scattering experiment?
Q 37.
State the location of electrons, protons and neutrons in an atom.
Q 38.
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 39.
What are cathode rays?
Q 40.
What is Atomic Number? Who coined this term?
Q 41.
What is the positive charge on the nucleus of an atom due to ?
Q 42.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 43.
Complete the following statements :
(a) Magnesium has 2 valence electrons in the......... shell.
(b)The valency of nitrogen in N2 molecule is........
(c)Isotopes have different mass numbers because their nuclei contain different number of........
(d) Some boron atoms have mass number 10 and some have mass number 11. These boron atoms with different mass numbers are called............
Q 44.
What is the mass of proton as compared to electron?
Q 45.
Fill in the blanks :
Co-60 a radio isotope is used in treatment of __________.
Q 46.
Which shell of an atom can accommodate a maximum of
(a) 8 electrons?
Q 47.
What is a neutron ? State its relative mass and charge.
Q 48.
Name the radioactive isotope which is used in the treatment of cancer.
Q 49.
State one use of radioactive isotopes in industry.
Q 50.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
