question_answer1)
What is the charge and mass of a neutron?
question_answer2)
Which sub-atomic particles of an atom are responsible for
atomic mass?
question_answer3)
Why did Rutherford select a gold foil in his a-ray
scattering experiment?
question_answer4)
What are isotopes?
question_answer5)
In the notation of nitrogen 
what
do the numbers 14 and 7 denote?
question_answer6)
Atomic number of an element is 12. What is its valency?
question_answer7)
The atomic number of neon is 10. Write its electronic
configuration.
question_answer8)
Identify the pair of isotopes from the following
question_answer10)
Who discovered neutron?
question_answer12)
What is the difference between Na and 
in terms of number of
electrons?
question_answer13)
If 
has 12
protons and 12 neutrons, what is its atomic number and mass number?
question_answer16)
What happens to an element ' Z' if its atom gains 3
electrons?
question_answer17)
If 
contains
18 electrons, what is its atomic number?
question_answer18)
Name the particles which are present in the extra nuclear
part of the atom.
question_answer19)
Name an element which does not contain neutron.
question_answer21)
What are cathode rays?
question_answer22)
Which isotope is used to cure cancer?
question_answer23)
Where are the valence electrons located in an atom?
question_answer24)
What are canal rays?
question_answer25)
What constitutes nucleus of an atom?
question_answer26)
Write the symbol of an element having atomic number 18 and
mass number 40.
question_answer28)
Which radioisotope is used to determine the age of old
wooden objects?
question_answer32)
What is the electronic configuration of (Rb (37)?
question_answer33)
What is the electronic configuration of Ca(20)?
question_answer34)
Which isotope of hydrogen contain same number of
electrons, protons and neutrons?
question_answer35)
What is the electronic configuration of 
?
question_answer37)
An atom has equal number of electrons and protons. Justify
the statement.
question_answer39)
Who gave the first model of an atom?
question_answer40)
What -will-be, the-valency of an atom with 3 protons and 4
neutrons?
question_answer42)
What does Rutherford's 
particle
scattering experiment shows?
question_answer43)
What is the radius of nucleus?
question_answer44)
For a neutral atom, what equals to the number of protons?
question_answer46)
Which isotope is used in thyroid scan?
question_answer47)
Give example of any two isobars.
question_answer48)
What is the electronic distribution in the Mg atom?
question_answer53)
What is then n/p ratio of
Ra?
question_answer54)
What is the n/p ratio of 
V?
question_answer58)
Write any two observations which support the
fact that atoms are divisible.
question_answer59)
Will
and 
have different valencies?
Justify your answer.
question_answer60)
Write the drawbacks of Rutherford's model of an atom.
question_answer75)
Why are electrons known as planetary electrons?
question_answer76)
What are scintillations?
question_answer78)
Determine the valency of oxygen and sulphur.
question_answer81)
What is the colour of electron, proton and neutron? Give
explanation.
question_answer87)
Why do helium, neon and argon have a zero valency?
Explain.
question_answer95)
Enlist the conclusions drawn by Rutherford from his a-ray
scattering experiment.
question_answer117)
How are the electrons distributed in different orbits
(Shells)?
question_answer119)
Give some characteristic features of anode rays.
question_answer125)
Draw
a sketch of Bohr's model of an atom with three shells.
question_answer126)
What
are canal rays?
question_answer127)
Which
subatomic particle is absent in an ordinary hydrogen atom?
question_answer128)
Name
a nucleus which does not contain neutron.
question_answer129)
Which
has greater mass?a proton or an electron?
question_answer134)
Write
the electronic configuration of an element whose atomic number is 12.
question_answer136)
What
do you understand by ground state of an atom?
question_answer137)
What
is the valency of sodium atom (atomic number 11)?
question_answer138)
What
is the maximum number of electrons which can be accommodated in 'N' shell?
question_answer140)
What
will be the valency of an atom if it contains 3 protons and 4 neutrons?
question_answer142)
Which
of the following pairs are isotopes?
(i) 
(ii) 
question_answer143)
Out
of elements 
and 
which
is chemically more reactive and why?
question_answer146)
Give
two important application of radioactive isotopes.
question_answer147)
Which
isotope of hydrogen is present in heavy water?
question_answer151)
What
are the limitations of J.J. Thomson's model of the atom?
question_answer152)
What
are the limitations of Rutherford's model of the atom?
question_answer153)
How
do you know that nucleus is very small as compared to the size of atom?
question_answer154)
Write
two characteristics of the canal rays.
question_answer155)
Compare
the properties of electrons, protons and neutrons.
question_answer156)
Write
the distribution of electrons in carbon and sodium atoms.
question_answer161)
Na+
has completely filled K and L shells. Explain.
question_answer163)
How
will you find the valency of chlorine, sulphur and magnesium?
question_answer165)
Define
valency by taking examples of silicon and oxygen.
question_answer167)
If
Z = 3, what would be the valency of the element? Also, name the element.
question_answer168)
Find
out the valency of the atoms represented by the Figs. (a) and (b)
question_answer172)
Write
the electronic configuration of any one pair of isotopes and isobars.
question_answer182)
Why
do isotopes show similar chemical properties?
question_answer183)
What
are isotopes? Give one example.
question_answer184)
What
are isobars? Give one example.
question_answer189)
Why
do helium, neon and argon have a zero valency?
question_answer199)
Justify
the statement, Protons are constituents of all atoms'.
question_answer202)
9.
How many electrons will weigh 1 g?
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(i) What is wrong with this structure of atom?
(ii) Draw a correct representation of this atom.
(iii) Write the chemical formula of the chloride of this element.
