4
Q:

The reactivity of an atom arises from 

A) the existence of unpaired electrons in the valence shell B) the energy differences between the electron shells
C) the sum of the potential energies of all the electron shells D) the average distance of the outermost electron shell from the nucleus

Answer:   A) the existence of unpaired electrons in the valence shell



Explanation:

When atoms react they do so in order to reach the lowest energy, which is the most stable. The electrons orbitals will overlap in the way that reduces the energy the most. Orbitals of similar energy will produce the greatest stabilisation.The answer you gave isn't the whole story, it depends what species is reacting with what. The effective nuclear charge on the atom will affect the energy of the valance electrons.

 

Hence, the reactivity of an atom arises from the existence of unpaired electrons in the valence shell.

Subject: Chemistry
Exam Prep: AIEEE , Bank Exams , GATE
Job Role: Analyst , Bank Clerk
Q:

The percentage of nitrogen in the air is about

A) 74% B) 76%
C) 78% D) 80%
 
Answer & Explanation Answer: C) 78%

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

8 861
Q:

Methane contributes towards global warming so it is called a _________________ gas.

 

A) poisonous B) carcinogenic
C) infectious D) greenhouse
 
Answer & Explanation Answer: D) greenhouse

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

2 28614
Q:

Which of the following is a metal?

 

A) Sulphur B) Nitrogen
C) Oxygen D) No option is correct
 
Answer & Explanation Answer: D) No option is correct

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

1 9512
Q:

Which of the following group is NOT Dobereiner Triads?

 

A) Li, Na, K B) N, P Au
C) Cl, Br, I D) Ca, Sr, Ba
 
Answer & Explanation Answer: B) N, P Au

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

3 43573
Q:

Safety matches contain

A) Sulphur B) Phosphorus
C) Magnesium D) Potassium
 
Answer & Explanation Answer: B) Phosphorus

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams

3 835
Q:

Air ___________________ are the substances which contaminate the air.

A) Reactants B) Irritants
C) Resistants D) Pollutants
 
Answer & Explanation Answer: D) Pollutants

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

2 795
Q:

By using which foam the Researchers from Indian Institute of Technology – Bombay have made a low cost piezo resistive vibration sensor?

A) Only Polyurethane B) Only Polyethylene
C) Both Polyurethane and Polyethylene D) Neither Poly urethane nor Polyethylene
 
Answer & Explanation Answer: B) Only Polyethylene

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

5 857
Q:

Which of the following is NOT a compound?

 

A) Ammonia B) Milk
C) Sodiumchloride D) Chalk
 
Answer & Explanation Answer: B) Milk

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: Bank Exams

9 19340