Sagar Gupta

  [ATOMIC STRUCTURE] {for IIT-JEE}

[The ultimate question bank for all engineering and medical exams]

1) Which of the following is not part of Dalton's atomic theory?

A) All matter is composed of indivisible atoms.
B) Atoms of the same element can be different.
C) Compounds form when atoms combine in whole number ratios.
D) A chemical reaction involves rearrangement of atoms.

ANSWER= (B) Atoms of the same element can be different.  
Explain:- This statement was not included in Dalton's Atomic Theory. Atoms of same element are different in form of Isotopes. In fact, John Dalton proposed that "All atom of an element are identical in all respect, but atoms of different elements differ". 

2) What determines light intensity in a cathode ray tube? 

A) current 
B) voltage
C) the fluorescence of screen
D) momentum of electrons

ANSWER= (D) momentum of electrons 
Explain:-  Moving electrons have some momentum which gives intensity of light emitted from fluorescent screen due to bombardment of electrons. 

 

3) An element  : 

                                                   [ODISHA JEE]

A) has one type of atom
B) has two or more types of atoms
C) has constant boiling point
D) has constant melting point

ANSWER= (A) has one type of atom
Explain:- Each element is made up of just one type of atom

 

4) The increasing order (lowest first) for the values of e/m for electron (e), proton (p), neutron (n) and alpha-particle (α) is :

A) e, p, n, α
B) n, p, e, α
C) n, p, α, e
D) n, α, p, e

ANSWER= (D) n, α, p, e
Explain:- 

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