Download App

Science [2 Mark Questions]

Periodic Classification of Elements · UP Board (UPMSP) STD 10 (UPMSP - English Medium). 4 questions.

Questions

[2 Mark Questions]

🎯

Test yourself on this topic

4 questions · timed · auto-graded

Question 12 Marks
InMendele′ ev’s Periodic Table the elements were arranged in the increasing order of their atomic masses. However, cobalt with atomic mass of 58.93amu was placed before nickel having an atomic mass of 58.71amu. Give reason for the same.
Answer
In Mendeleev's periodic table, the reasons for placing cobalt (Co) before nickel (Ni) though its atomic mass is higher than that of nickel, are:
  1. Cobalt was placed in the group of rhodium (Rh) and iridium (Ir) because it exhibits the properties similar to them.
  2. Similarly Nickel was placed with elements like palladium (Pd) and platinum (Pt) having properties similar to it.
View full question & answer→
Question 22 Marks
Can the following groups of elements be classified as Dobereiner's triad?
  1. Na, Si, Cl.
  2. Be, Mg, Ca.
Atomic mass of Be 9; Na 23; Mg 24; Si 28; Cl 35; Ca 40. Explain by giving reason.
Answer
  1. No, because all these elements do not have similar properties although the atomic mass of silicon is average of atomic masses of sodium (Na) and chlorine (Cl).
  2. Yes, because they have similar properties and the mass of magnesium (Mg) is roughly the average of the atomic mass of Be and Ca.
View full question & answer→
Question 32 Marks
Three elements A, B and C have 3, 4 and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the Modern Periodic Table. Also, give their valencies.
Answer
A belongs to Group 13, B belongs to Group 14 and C belongs to Group 2. Valency of A is 3, that of B is 4 and that of C is 2.
View full question & answer→
Question 42 Marks
Elements have been arranged in the following sequence on the basis of their increasing atomic masses.
F, Na, Mg, Al, Si, P, S, Cl, Ar, K.
  1. Pick two sets of elements which have similar properties.
  2. The given sequence represents which law of classification of elements?
Answer
  1. The elements that have similar properties belong to the same group. From the list of elements available, elements which belong to same group are:
Na, K (Alkali metals); F, Cl (Halogens)
  1. The sequence is according to Newland’s law of octaves.
View full question & answer→
Generate Paper FreeAll Periodic Classification of Elements topics
[2 Mark Questions] - Science STD 10 Questions - Vidyadip