Exam. Class-10, Science and Technology, Chap. 2: Periodic Classification of Elements.

Question paper, Class-10, Science and Technology, Chap. 2: Periodic Classification of Elements.

Practice Question Paper

Subject: General Science (Part 1)

Chapter 2: Periodic Classification of Elements

Time: 45 Minutes

Q.1. Fill in the blanks: (3 Marks)

1. The horizontal rows in the modern periodic table are called __________.  
2. The property of an element to form an anion by accepting electrons is called __________ character.  
3. Up to __________ elements are known to date in the modern periodic table.  

4. The number of electrons in the outermost shell of alkali metals is......

Q. 2. True or False? (3 Marks)

1. Properties of elements are a periodic function of their atomic masses.  
2. The number of valence electrons in elements going down a group changes continuously.
3. According to Dobereiner, the atomic mass of the middle element of a triad is roughly equal to the average atomic mass of the other two elements.  

Q.3. Match the following: (3 Marks)

Column 'A'                      Column 'B'

i. Modern Periodic Law  a. Henry Moseley

ii. Triads                           b. Dobereiner

iii. Octaves                        c. Newlands

                                          d. Mendeleev

Q.4. State the Laws / Principles: (2 Marks)

1. State Mendeleev’s Periodic Law.  
2. State Modern Periodic Law.  
3. Newlands’ Law of Octaves

Q.5. Write Definitions / Scientific Terms: (2 Marks)

1. Atomic Radius:  
2. Electronegativity:  

Q.6. Answer in one sentence: (3 Marks)

1. Why are the elements of group 1 called alkali metals?  
2. What is the cause of the nonmetallic character of elements?  
3. State the total number of blocks into which the modern periodic table is divided.  

Q.7. Give short answers/scientific reasons: (6 Marks)

1. Atomic radius goes on decreasing while going from left to right within a period. Explain why.  
2. Elements belonging to the same group have similar chemical properties. Give reason.

3. Metallic character goes on decreasing while going from left to right in a period.

4. An element has its electronic configuration as 2,8,2. Answer the following:  

a) What is the atomic number of this element?  

b) To which period does this element belong?  

c) What is the valency of this element?

Q.8. Answer the following (Longer Answer): (3 Marks)

•  Explain the merits of Mendeleev’s periodic table.

Q.9. Write the names from the description.

a. The period with electrons in the shells K, L, and M. 

b. The group with valency zero.

c. The family of nonmetals having valency one.

d. The family of metals having valency one.

e. The family of metals having valency two.

f. The metalloids in the second and third periods.

g. Nonmetals in the third period.

h. Two elements having valency 4.