The approach of classifying various elements in different groups based on their properties is known as periodic classification. Elements are classified in different periods and groups in the periodic table based on their atomic numbers. The vertical columns in the periodic table are known as the groups. There are eighteen such groups in the modern periodic table. However, the horizontal rows are known as the periods. There are seven such periods in the modern periodic table.
Download Class 10 Chemistry Worksheet on Chapter 5 Periodic Classification of Elements Set 1 PDF
CBSE Class 10 Chemistry Chapter 5 Periodic Classification of Elements Worksheet – Set 1
Q1. Name the scientist who first showed that an element’s atomic number is a more fundamental property than its atomic mass.
(a) Henry Moseley
(b) Dimitri Mendeleev
(c ) Both (a) and (b)
(d) None of the above
Q2. Which of the following group belongs to the actinide series?
(a) Th, Pa and U
(b) Ce, Pr and Nd
(c ) Ba, La and Hf
(d) Pt, Au and Ag
Q3. What is the unit of ionisation energy?
(a) J / m
(b) KJ / mol
(c ) J.m
(d) None of the above
Q4. True or False: Elements in a group have consecutive atomic numbers.
(a) True
(b) False
(c ) Neither true nor false
(d) None of the above
Q5. On moving from left to right in a period in the periodic table, the size of the atom ______.
(a) Increases
(b) Decreases
(c ) First decreases than increases
(d) Does not change appreciably
Q6. What is the base of the elements’ arrangement in the Mendeleev periodic table?
Q7. Elements X, Y and Z belong to Dobereiner’s triad. If the atomic mass of X is seven and Z is thirty-nine, What will be the atomic mass of Y?
Q8. What do you understand by Dobernier’s law of triads?
Q9. Why are there some voids in the Mendeleev periodic table?
Q10. Why does hydrogen occupy a unique position in the modern periodic table?
Q11. What do you understand by groups and periods? How many groups and periods are there in the modern periodic table?
Q12. What do you understand by Newland’s law of octave? Explain its significance.
Q13. A metal M forms an oxide of the formula M2O3. It is in the third period of the modern periodic table. What is the atomic number and valency of the metal?
Q14. Which of the following fluorine, chlorine, bromine and iodine do not fit in Dobereiner’s law of triad?
Q15. Name any two elements whose valency is equivalent to their group number?
Q16. Calcium’s atomic number is 20. Will it be more or less reactive than magnesium?
Q17. Why does carbon have a valency of four while chlorine has a valency of one?
Q18. A metal M is in the 13th group of the modern periodic table. What is the valency of the metal?
Q19. What is the formula of chloride of element X having atomic number 20?
Q20. Among Calcium, Magnesium and Strontium, which one will have an atom of the most significant size?
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Read Also:
- Periodic Classification Of Elements
- Classification of Elements and Periodicity in Properties
- Periodic Table
- Modern Periodic Table And Its Significance
- Periodic Properties Of Elements and Their Significance
- Modern Periodic Law
- Periodic Table of Elements
- Chemistry Concept Questions and Answers
- Newland’s Law of Octaves and Dobereiner’s Triads
- Classification of Elements and Periodicity in Properties
- Mendeleev Periodic Table
- Class 10 Chemistry Chapter 5 – Periodic Classification of Elements Important Questions with Answers
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