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

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: Which of the following is the correct set of elements to Dobereiner’s triads ?

• a)

  

• b)

  

• c) Data insufficient
• d)

  

Answer:

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

More Questions.........................

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