Download App

Classification of Elements and Periodicity in Properties — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistryClassification of Elements and Periodicity in Properties5 Marks
Question
What is the basic difference in approach between the Mendeleev’s Periodic Lawand the Modern Periodic Law?
✓

Answer

According to Mendeleev’s periodic law, the physical and chemical properties of the elements are periodic functions of their atomic masses, but according to modern periodic law, the physical and chemical properties of the elements are periodic functions of their atomic numbers.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Classification of Elements and Periodicity in Properties→Classification of Elements and Periodicity in Properties — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

  1. Predict the acidic, basic or neutral nature of the following salts:

NaCN, KBr, NaNO2, NH4NO3

  1. What is the minimum volume of water required to dissolve 1 g of calcium sulphate at 298K? (For calcium sulphate Ksp is 9.1 × 10-6).
  2. At 450K ; Kp = 2.0 × 1010bar-1 for the reaction at equilibrium:

​​​​​​​​​​​​​​$2\text{SO}_2(\text{g})+\text{O}_2(\text{g})\rightleftharpoons2\text{SO}_3(\text{g})$

What is Kc at this temperature?

→
Derive the relationship between equilibriumconstant (K), reaction constant (Q) and Gibbs energy (G) and explain spontaneity of reaction with help of it.
→
Differentiate between the principle of estimation of nitrogen in an organic compound by,
  1. Dumas method.
  2. Kjeldahl’s method.
→
Four moles of PCl5 are heated in a closed 4dm3(L) container to reach equilibrium at 400K. At equilibrium 50% of PCl5 is dissociated. What is the value of Kc for the dissociation of PCl5 into PCl3 and Cl2 at 400K.
→
1. What is the general molecular formula of saturated monohydric alcohols?
2. Write structural formulae for compounds named as-
a. 1-Bromoheptane
b. 5-Bromoheptanoic acid
→
Define octet rule. Write its significance and limitations.
→
Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2 is linear. Explain this on the basis of dipole moment.
→
A reaction between ammonia and boron trifluoride is given below:
: NH3 + BF3 → H3N: BF3
Identify the acid and base in this reaction. Which theory explains it? What is the hybridisation of B and N in the reactants?
→
What is meant by the term bond order? Calculate the bond order of : $\text{N}_2,\text{O}_2,\text{O}_2^+$ and $\text{O}_2^-$
→
Which out of NH3 and NF3 has higher dipole moment and why?
→