CBSE Class 11 Chemistry Classification of Elements and Periodicity in Properties MCQs Set A

Question : Periodic classification of elements is used to examine the

a) Both

b) periodic trends in physical properties of elements

c) periodic trends in chemical properties of elements

d) None of these

Answer : Both

Question : Cl, Br, I, if this is Dobereiner’s triad and the atomic masses of Cl and I are 35.5 and 127 respectively the atomic mass of Br is

a) 81.25

b) 162.5

c) 91.5

d) 45.625

Answer : 81.25

Question : If the two members of a Dobereiner triad are phosphorus and antimony, the third member of this triad is

a) arsenic

b) iodine

c) sulphur

d) calcium

Answer : arsenic

Question : The law of triads is applicable to a group of

a) Cl, Br, I

b) Na, K, Rb

c) C, N, O

d) H, O, N

Answer : Cl, Br, I

Question : In 1800, only _____X _____ elements were known. Here, X refers to

a) 31

b) 92

c) 63

d) None of these

Answer : 31

Question : Johann Doberiner gave the idea of trends among physical and ...X... of several groups of three elements. Here, X refers to

a) chemical properties

b) atomic number

c) atomic mass

d) None of these

Answer : chemical properties

Question : On which of the following Dobereiner’s Triad law is not applicable?

a) F, Cl, Br

b) Cl, Br, I

c) Ca, Sr, B

d) Li, Na, K

Answer :  F, Cl, Br

Question : Newlands could classify elements only upto

a) calcium

b) copper

c) chlorine

d) chromium

Answer : calcium

Question : According to Newlands theory, when elements are arranged in the order of increasing atomic weight which number element had similar properties to the first element.

a) eighth

b) third

c) seventh

d) sixth

Answer :  eighth

Question : Lothar Meyer plotted the physical properties such as atomic volume, melting point and ...X... against atomic weight. Here, X refers to

a) boiling point

b) None of these

c) mass

d) surface tension

Answer : boiling point

Question : The most significant contribution towards the development of periodic table was made by

a) Mendeleev

b) Dalton

c) Avogadro

d) Cavendish

Answer : Mendeleev

Question : Noble gases were included in Mendeleev’s periodic table in the

a) None of these

b) 7th group

c) 1st group

d) 8th group

Answer : None of these

Question : Mendeleev classified elements in

a) seven periods and nine groups

b) eight periods and seven groups

c) eight periods and eight groups

d) increasing order of atomic groups

Answer : seven periods and nine groups

Question : Select the correct chronological order for the discoveries of the following scientists.

Dobereiner, Newlands, Chancourtois, Mendeleev

a) Dobereiner, Chancourtois, Newlands, Mendeleev

b) Dobereiner, Newlands, Chancourtois, Mendeleev

c) Chancourtois, Newlands, Dobereiner, Mendeleev

d) Chancourtois, Dobereiner, Newlands, Mendeleev

Answer : Dobereiner, Chancourtois, Newlands, Mendeleev

Question : Who developed long form of the periodic table?

a) Neils Bohr

b) Moseley

c) Lothar Meyer

d) Mendeleev

Answer : Neils Bohr

Question : At present, how many elements are known

a) 118

b) 112

c) 110

d) 113

Answer : 118

Question : Which of the scientists given below discovered that periodic table should be based on the atomic number ?

a) Moseley

b) Mendeleev

c) Newlands

d) Lothar Meyer

Answer : Moseley

Question : How many elements are there in 6th period of periodic table?

a) 32

b) 8

c) 18

d) 30

Answer : 32

Question : Modern periodic table is based on the atomic number of the elements. The experiment which proved the significance of the atomic number was

a) Mosley’s work on X-ray spectra

b) Bragg’s work on X-ray diffraction

c) Discovery of X-rays by Rontgen

d) Mulliken’s oil drop experiment

Answer : Mosley’s work on X-ray spectra