47
Q:

# An atom has 7 electrons in its M - shell and contains 18 neutrons in its nucleus. What is its mass number

 A) 25 B) 27 C) 35 D) 43

Explanation:

According to Bohr model, Each shell can occupy 2$n2$ electrons in their orbits where n=1,2,3.. for K,L,M,..

The atom has 2 electrons in k, 8 electrons in L and 7 electrons in M = 2 + 8 + 7 = 17

And given that its nucleus has 18 neutrons

=> its mass number = number of (electrons + neutrons ) = 17 + 18 = 35

Subject: Chemistry
Q:

Which of the following is used to remove the green colour from glass?

 A) Manganese dioxide B) Sulphur dioxide C) Titanium dioxide D) Silicon dioxide

Explanation:

Filed Under: Chemistry
Exam Prep: Bank Exams

0 100
Q:

Which of the following statement(s) is/are CORRECT?

I. Carbon compounds linked by only single bond are called saturated compounds.

II. Carbon compounds having double or triple bonds are called unsaturated compounds.

III. Saturated carbon compounds are more reactive than unsaturated carbon compounds.

 A) Only I and II B) Only I and III C) Only II and III D) All I, II and III

Explanation:

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams

0 83
Q:

What is the maximum number of electrons that the  outermost shell can have?

 A) 2 B) 6 C) 8 D) none

Explanation:

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams

1 98
Q:

The first electron shell which is the nearest to the nucleus never holds more than 'n' electrons, where 'n' is equal to:

 A) 8 B) 4 C) 6 D) 2

Explanation:

Filed Under: Chemistry
Exam Prep: Bank Exams

0 96
Q:

What is the atomic mass of Zirconium?

 A) 91.22 B) 89.22 C) 88.22 D) 90.22

Explanation:

Filed Under: Chemistry
Exam Prep: Bank Exams

2 642
Q:

How many types of isotopes does Scandium have?

 A) 9 B) 7 C) 10 D) 13

Explanation:

Filed Under: Chemistry
Exam Prep: Bank Exams

2 672
Q:

Which of the following has the lowest melting point?

 A) Zinc B) Silver C) Lead D) Tin

Explanation:

Filed Under: Chemistry
Exam Prep: Bank Exams

2 831
Q:

What is the bond angle (in degrees) in the structure of a benzene molecule?

 A) 60 B) 150 C) 90 D) 120