Question 76.
Vertical columns are called as –
(a) Groups
(b) Period
(c) Rows
(d) None
Answer: (a) Groups
Question 77.
How many groups are there in the periodic table?
(a) 18
(b) 8
(c) 28
(d) 17
Answer: (a) 18
Question 78.
The valence shell of element A contains 3 electrons while the valence shell of element B contains 6
electrons. If A combines with B, the probable chemical formula of the compound is
(a) AB2
(b) A2B
(c) A2B3
(d) A3B2
Answer: (c) A2B3
Question 79.
Which one of the following elements exhibit maximum number of valence electrons?
(a) Na
(b) Al
(c) Si
(d) P
Answer: (d) P
Question 80.
Which group was added in Mendleev’s periodic table?
(a) I group
(b) Zero group
(c) VIII group
(d) V group
Answer: (b) Zero group
Question 81.
Element ‘A’ has electronic configuration 2, 7; ‘B’ has electronic configuration 2, 8, 5 and ‘C’ has
electronic configuration 2, 8, 7. Which two elements will exhibit similar chemical properties?
(a) A and C
(b) A and B
(c) B and C
(d) None of these
Answer: (a) A and C
Question 82.
What is the special name given to the 17th group?
(a)) chalcogens
(b)) halogens
(c)) alkali metals
(d)) inert gases
Answer: (b) halogens
Question 83.
Which of the following are the characteristics of isotopes of an element?
(i) Isotopes of an element have same atomic masses
(ii) Isotopes of an element have same atomic number
(iii) Isotopes of an element show same physical properties
(iv) Isotopes of an element show same chemical properties
(a) (i), (iii) and (iv)
(b) (ii), (iii) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Answer: (b) (ii), (iii) and (iv)
Question 84.
An element-X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic
table does it belong?
(a) Group 1
(b) Group 4
(c) Group 2
(d) Group 3
Answer: (b) Group 4
Question 85.
Chalcogens are ?
(a)) ore forming
(b)) salt forming
(c)) hydroxide forming
(d)) None
Answer: (a) ore foming
Question 86.
Which of the following properties does not match element of the halogen family?
(a) They have seven electrons in their valence shell.
(b) They are highly reactive.
(c) They are metallic in nature.
(d) They are diatomic in their molecular form.
Answer: (c) They are metallic in nature.
Question 87.
The electronic configuration of the atom of an element X is 2, 4, 8. In the modern periodic table, the
element X is placed in:
(a) 2nd group
(b) 4th group
(c) 14th group
(d) 8th group
Answer: (c) 14th group
Question 88.
Atomic mass is equal to the sum of ____.
(a)) P+N
(b)) P+E
(c)) Number of Protons
(d)) Number of neutrons
Answer: (b) Her mother and grandmother went to the hospital
Question 89.
What is the order of the metallic character down the group?
(a) it decreases as new shells are added to the element
(b) it increases as electrons move away from the nucleus
(c) increases as new atoms are added in the same shell
(d) it decreases as the effective nuclear charge on the electron increases
Answer: (b) it increases as electrons move away from the nucleus
Question 90.
Which of the following element would lose an electron easily?
(a) Mg
(b) Na
(c) K
(d) Ca
Answer: (c) K
Question 91.
What is the trend of valency along the periods in the modern periodic table?
(a) it increases from left to right
(b) it decreases from right to left
(c) it increases and then decreases
(d) it decreases and then increases
Answer: (c) it increases and then decreases
Question 92.
Electronegativity is defined as the ability of an element to form bonds by gaining electrons. How does
the electronegativity of elements vary across the periods?
(a) it increases as the number of shells increases
(b) decreases as the number of shells decreases
(c) increases as the more of electrons are added to the same shell
(d) it decreases as the more of electrons are added to the same shell
Answer: (c) increases as the more of electrons are added to the same shell
Question 93.
Name the most electronegative element of Periodic table ?
(a)) Chlorine
(b)) Bromine
(c)) Fluorine
(d)) Iodine
Answer: (c) Flurine
Question 94.
Write valency of Iron ?
(a) 2
(b) 3
(c) 0
(d) 2, 3
Answer: (d) 2,3
Question 95.
Boron is a non-metal and is placed under group 13 and period 2. How can boron form bonds with other
elements?
(a) by sharing 5 electrons
(b) by sharing 3 electrons
(c) by sharing 2 electrons
(d) by sharing 1 electron
Answer: (b) by sharing 3 electrons
Question 96.
Electron affinity is ____.
(a) always negative
(b) always positive
(c) can be negative or positive
(d) zero
Answer: (c) can be negative or positive
Question 97.
The element A, B, C, D and E have atomic numbers 9, 11, 17, 12 and 13 respectively. The pair of elements
which belongs to the same group of the periodic table is:
(a) A and B
(b) B and D
(c) A and C
(d) D and E
Answer: (c) A and C
Question 98.
Out of Mg and Al which has higher ionisation energy?
(a) Mg
(b) both have same
(c) Al
(d) none
Answer: (c) Al
Question 99.
Ionisation energy is measured in –
(a)) KJ/g
(b)) J/mole
(c)) KJ/mol
(d)) none
Answer: (c) KJ/mol
Question 100.
A student learns that the atomic size depends on the atomic radius of the elements. How does the atomic
radius of elements in the third-period change as one goes from sodium to argon?
(a) Option 1: atomic radius increases from sodium to argon
(b) atomic radius decreases from sodium to argon
(c) atomic radius increases as new shells are added
(d) atomic radius decreases due to the addition of new shells
Answer: (b) atomic radius decreases from sodium to argon