Periodic Classification of Elements Class 10 MCQs Questions with Answers
Question 1.
The total number of periods in Mendeleev’s periodic table is:
(a) 7
(b) 8
(c) 9
(d) 15
Answer:
(a) 7
Question 2.
On moving from left to right in a short period, the valency of elements with respect to hydrogen:
(a) increases
(b) decreases
(c) remains unchanged
(d) first increases from 1 to 4 then decreases from 4 to 1.
Answer:
(d) first increases from 1 to 4 then decreases from 4 to 1.
Question 3.
On moving from left to right in a period :
(a) electropositive nature of elements increases
(b) metallic character of elements increases
(c) ionic radius of elements increases
(d) basic nature of oxides of elements decreases.
Answer:
(d) basic nature of oxides of elements decreases.
Question 4.
On moving down a group:
(a) ionic radius decreases
(b) density decreases
(c) electronegativity increases
(d) metallic character increases.
Answer:
(d) metallic character increases.
Question 5.
One of the defects of Mendeleeff’s periodic table is that:
(a) halogens are placed in the same group
(b) on its basis properties of known elements cannot be predicted
(c) elements of dissimilar properties are placed in the same group
(d) periodic table is not based on any fundamental principle.
Answer:
(c) elements of dissimilar properties are placed in the same group
Question 6.
Modern periodic table is based on:
(a) atomic weight
(b) equivalent weight
(c) molecular weight
(d) atomic number
Answer:
(d) atomic number
Question 7.
The number of groups in Mendeleeff’s periodic table is:
(a) 7
(b) 8
(c) 9
(d) 16
Answer:
(c) 9
Question 8.
Modern periodic law is given by:
(a) Mendeleeff
(b) Moseley
(c) Priestly
(d) Davy.
Answer:
(b) Moseley
Question 9.
Element with 18 atomic number is in:
(a) zero group
(b) VIII group
(c) period fourth
(d) transition series.
Answer:
(a) zero group
Question 10.
Number of elements in second period is:
(a) 2
(b) 8
(c) 10
(d) 18
Answer:
(b) 8
Question 11.
(i) Li and (ii) Be show diagonal relation with:
(a) (i) Mg and (ii) Al
(b) (i) Na (ii) Mg
(c) (ii) K and (ii) B
(d) (i) Na (ii) K
Answer:
(a) (i) Mg and (ii) Al
Question 12.
In the periodic table with the increase in atomic number in any group the …….. increases.
(a) electropositive character
(b) ionization potential
(c) valency
(d) chemical reactivity.
Answer:
(a) electropositive character
Question 13.
Element with atomic number 17 is placed in:
(a) VII period, VII group
(b) III period, VII group
(c) IV period, VII group
(d) II period, VI group.
Answer:
(b) III period, VII group
Question 14.
Alkaline metals are:
(a) Be, Mg, Ca
(b) Li, Na, K
(c) B, Al, Ga
(d) Cu, Ag, Au.
Answer:
(b) Li, Na, K
Question 15.
Which of the following elements will have maximum electro-positive character:
(a) F
(b) Mg
(c) Na
(d) K.
Answer:
(d) K.
Question 16.
Maximum valency with respect to oxygen is found in elements of:
(a) I group
(b) VII group
(c) IV group
(d) 0 group.
Answer:
(b) VII group
Question 17.
Maximum valency with respect to hydrogen is found in elements of:
(a) I group
(b) VII group
(c) IV group
(d) 0 group.
Answer:
(c) IV group
Question 18.
Characteristics of elements depend on:
(a) no. of protons present in atom
(b) no. of neutrons present in atom
(c) mass of the atom
(d) none of these.
Answer:
(a) no. of protons present in atom
Question 19.
In a period from left to right the metallic character of elements:
(a) increases gradually
(b) decreases gradually
(c) remains constant
(d) first increases an then decreases.
Answer:
(d) first increases an then decreases.
Question 20.
Which of the following is the most electronegative?
(a) Ne
(b) F
(c) Ar
(d) Br.
Answer:
(a) Ne
Question 21.
Formula of chloride of an element is MCl2. Write the formula of its oxide.
(a) MO2
(b) MO
(c) M2O3
(d) M2O
Answer:
(b) MO
Question 22.
Neon is an:
(a) Alkali metal
(b) Inert Gas
(c) Metalloid
(d) Transition element
Answer:
(b) Inert Gas
Question 23.
Diagonally related elements are:
(a) Li and Be
(b) Li and Mg
(c) Li and Na
(d) Bi and Si
Answer:
(b) Li and Mg
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