WorksheetsChemistry 9 Structure of atom
Total questions: 34
Worksheet time: 17mins
Name
Class
Date
1.
Rutherford's alpha particle scattering experiment led to the discovery of :
a)
Nucleus
b)
Electrons
c)
Protons
d)
Neutrons
2.
Which of the following is the correct electronic configuration of sodium?
a)
2, 8, 1
b)
8, 2, 1
c)
2, 1, 8
d)
2, 8, 2
3.
The particle not present in an ordinary hydrogen atom is :
a)
neutron
b)
proton
c)
nucleus
d)
electron
4.
The subatomic particle called electron was discovered by:
a)
J.J. Thomson
b)
Neils Bohr
c)
James Chadwick
d)
Eugen Goldstein
5.
Which of the following represents the correct electron distribution in magnesium ion?
a)
2, 8
b)
2, 8, 1
c)
2, 8, 2
d)
2, 8, 3
6.
The correct electronic configuration of a chloride ion is:
a)
2, 8, 8
b)
2, 8
c)
2, 8, 4
d)
2, 8, 7
7.
Goldstein's experiments which involved passing high voltage electricity through gases at very low pressure resulted in the discovery of :
a)
proton
b)
electron
c)
nucleus
d)
neutron
8.
The ion of an element has 3 positive charges. The mass number of atom of this element is 27 and the number of neutrons is 14.
What is the number of electrons in the ion?
a)
10.0
b)
13.0
c)
14.0
d)
16.0
9.
The first model of an atom was given by :
a)
J.J. Thomson
b)
Neils Bohr
c)
Ernest Rutherford
d)
Eugen Goldstein
10.
Which of the following statement is always correct?
a)
an atom has equal number of electrons and protons
b)
an atom has equal number of electrons and neutrons
c)
an atom has equal number of protons and neutrons
d)
an atom has equal number of electrons, protons and neutrons
11.
The mass number of two atoms X and Y is the same (40 each) but their atomic numbers are different (being
20 and 18 respectively). X and Y are examples of :
a)
isobars
b)
chemically similar atoms
c)
isotopes
d)
solid and liquid metals
12.
Which of the following statement is correct about the atom of an element?
a)
an atom can have only electron and proton but no neutron
b)
an atom can have only protons and neutrons but no electrons.
c)
an atom can have only electrons and neutrons but no protons
d)
an atom must always have a proton, neutron and electron
13.
There are two species represented as 35 Cl and 37 Cl. Which of the following statement is correct regarding these species?
a)
they have the same number of protons
b)
they have different chemical properties
c)
their physical properties are the same
d)
they are isobars of the same element
14.
The radioactive isotope used in the treatment of cancer is
a)
cobalt-60
b)
plutonium-239
c)
arsenic-74
d)
iodine-131
15.
Elements having valency 1 are:
a)
either metals or non-metals
b)
always metals
c)
always non-metals
d)
always metalloids
16.
In a sample of ethyl ethanoate (CH3COOC2H5), the two oxygen atoms have the same number of electrons but different number of neutrons. Which of the following is the correct reason for it?
a)
the two oxygen atoms are isotopes
b)
one of the oxygen atoms has gained electrons
c)
one of the oxygen atoms has gained protons
d)
the two oxygen atoms are isobars
17.
Which of the following elements does not exhibit electrovalency?
a)
carbon
b)
calcium
c)
chromium
d)
cadmium
18.
The number of valence electrons in a graphite atom is :
a)
4.0
b)
2.0
c)
3.0
d)
5.0
19.
The atomic numbers of four elements A, B, C and D are 12, 13, 15 and 3 respectively. The element which cannot form a cation is :
a)
C
b)
A
c)
B
d)
D
20.
For an element, Z = 9. The valency of this element will be:
a)
1.0
b)
2.0
c)
3.0
d)
4.0
21.
Four elements W, X, Y and Z contain 8, 11, 9 and 17 protons per atom respectively. The element which cannot form an anion is most likely to be :
a)
X
b)
Y
c)
Z
d)
W
22.
There are four elements P, Q, R and S having atomic numbers of 4, 18, 10 and 16 respectively. The element which can exhibit covalency as well as electrovalency will be:
a)
S
b)
P
c)
Q
d)
R
23.
The atomic number of an element X is 8 and that of element Y is 4. Both these elements can exhibit a valency of
a)
2.0
b)
1.0
c)
3.0
d)
4.0
24.
The isotopes of an element contain:
a)
different number of neutrons but same number of protons
b)
same number of neutrons but different number of protons
c)
same number of neutrons but different number of electrons
d)
different number of protons as well as different number of neutrons
25.
Which of the following correctly represent the electronic distribution in the Mg atom?
a)
2, 8, 2
b)
3, 8, 1
c)
1, 8, 3
d)
8, 2, 2
26.
Dalton’s atomic theory successfully explained
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportion
a)
(i), (ii) and (iv)
b)
(i), (ii) and (iii)
c)
(i), (iii) and (iv)
d)
(ii), (iii) and (iv)
27.
Which of the following statements about Rutherford’s model of atom are correct?
(i) Considered the nucleus as positively charged
(ii) Established that the α-particles are four times as heavy as a hydrogen atom
(iii) Can be compared to solar system
(iv) Was in agreement with Thomson’s model
a)
(i) and (iii)
b)
(ii) and (iii)
c)
(i) and (iv)
d)
only (i)
28.
Which of the following are true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic mass = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons
a)
(ii) and (iv)
b)
(i) and (ii)
c)
(i) and (iii)
d)
(ii) and (iii)
29.
In the Thomson’s model of atom, which of the following statements are correct?
(i) The mass of the atom is assumed to be uniformly distributed over the atom.
(ii) The positive charge is assumed to be uniformly distributed over the atom.
(iii) The electrons are uniformly distributed in the positively charged sphere.
(iv) The electrons attract each other to stabilise the atom.
a)
(i), (ii) and (iii)
b)
(i) and (iii)
c)
(i) and (iv)
d)
(i), (iii) and (iv)
30.
Rutherford’s a-particle scattering experiment showed that
(i) Electrons have negative charge.
(ii) The mass and positive charge of the atom is concentrated in the nucleus.
(iii) Neutron exists in the nucleus.
(iv) Most of the space in atom is empty.
Which of the above statements are correct?
a)
(ii) and (iv)
b)
(i) and (iii)
c)
(i) and (iv)
d)
(iii) and (iv)
31.
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
a)
10
b)
13
c)
14
d)
16
32.
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
(i) Rutherford’s atomic model
(ii) Thomson’s atomic model
(iii) Bohr’s atomic model
a)
(ii), (i) and (iii)
b)
(i), (ii) and (iii)
c)
(ii), (iii) and (i)
d)
(iii), (ii) and (i)
33.
An atom with 3 protons and 4 neutrons will have a valency of
a)
1
b)
3
c)
4
d)
7
34.
The electron distribution in an aluminium atom is
a)
2, 8, 3
b)
2, 8, 2
c)
8, 2, 3
d)
2, 3, 8
100 %
