MEDIUM
10th ICSE
IMPORTANT
Earn 100

In Mendeléev’s Periodic Table the elements were arranged in the increasing order of their atomic masses. However, cobalt with an atomic mass of 58.93 amu was placed before nickel having an atomic mass of 58.71 amu. Give reason for the same.

Important Questions on Periodic Classification of Elements

MEDIUM
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 5
The isotopes being having different atomic masses are placed at the same place by Mendeleev. Why?
HARD
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 2
How does the arrangement of elements in the modern periodic table remove the problem of the positioning of isotopes?
HARD
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 3
Write the defects of the long form of the periodic table.
HARD
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 4
List the anomalies of the Mendeleev periodic table which were renamed by Modern Periodic Law.
HARD
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 1
An element X belongs to 3rd period and group 13 of the Modern Periodic Table. Determine the valence electrons and the valency of X.
MEDIUM
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 1
An element X belongs to 3rd period and group 13 of the Modern Periodic Table. Write the molecular formula of the compound formed when X reacts with an element Y (atomic number = 8).
MEDIUM
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 1
An element X belongs to 3rd period and group 13 of the Modern Periodic Table. Write the name and the formula of the compound formed when X combines with chlorine.
EASY
10th ICSE
IMPORTANT
Science Chemistry>Chapter 5 - Periodic Classification of Elements>Practice Questions>Q 2
Which property of neon makes it useful in advertising signs?