10th Periodic Classification Of Elements CBSE Guess Question

Q1. What is atomic size?

Q2. What is valency?

Q3. A metal M forms an oxide having the formula M2O3. It belongs to the third period and 
thirteenth group of the Modern periodic table. Write the atomic number and valency of the element.

Q4. What were the two major shortcomings of Mendleev’s periodic table? How have these been removed in the modern periodic table?

Q5. Two elements X and Y have atomic numbers 12 and 16 respectively. Write the electronic configuration for these elements. To which period of the modern periodic table do these two elements belong? What type of bond will be formed between them and Why?

Q6. What were the two achievements of Mendleev’s periodic table? What was the basis of classification of elements in it?

Q7. Atomic radius decreases in moving from left to right in a period. Why?

Q8. Atomic radius increases down the group. Why?

Q9. In the modern periodic table a zig-zag line separates metals from non-metals. What are these elements called and why?

Q10. Tendency to lose electrons decreases as we move from left to right in a period. Why?

Q11. Tendency to lose electrons increases as we move from top to bottom in a group. Why?

Q12. How would the tendency to gain electrons change as you go from left to right across a period?

Q13. How would the tendency to gain electrons change as you go down a group?

Q14. An element X (2, 8, 2) combines separately with NO^{3 –} and SO₄^2- and PO₄^3- radicals.Write the formulae of the three compounds so formed. 

To which group of the periodic table does the element X belongs? Will it form covalent or ionic compound? Why?

Q15. Atomic number is considered to be a more appropriate parameter than atomic mass for

classification of elements in a periodic table. Why? 

How does atomic size of elements vary on moving from 
(i) left to right in a period 
(ii) from top to bottom in a group Give reasons for your answer.

Q16.How could the modern Periodic table remove various anomalies of Mendleev’s Periodic table?

Q17 Newland’s Law of octaves worked well with which type of elements?

Q18 Who deserves the main credit of classifying elements?

Q19 What is the fundamental property of elements?

Q20 Besides atomic masses, on what other basis were the elements arranged in the Mendleev’s periodic  table? 

Q21 Which chemical property of an element was treated as one of the basic property for classifying elements and why?

Q22 What is Mendleev’s periodic Law?

Q23 What name is given to vertical columns in Mendleev’s periodic table?

Q24 What name is given to horizontal rows in Mendleev’s periodic table?

Q25 While developing the Periodic table, at few places Mendleev inverted the sequence of some elements i.e. he placed an element with slightly greater atomic mass before the element of lower atomic mass. Why did he do so?

Q26 Though the atomic mass of cobalt (58.9) is greater than nickel (58.7) yet Co is placed before Ni in Mendleev’s periodic table. Why? 

Q27 Which elements did not exist at the time of Mendleev’s periodic classification? What name was given to these elements?

Q28 In what way hydrogen resembles alkali metals?

Q29 In what way hydrogen resembles halogens?

Q30 Why hydrogen cannot be given a fixed position in periodic table?