MEDIUM
9th CBSE
IMPORTANT
Earn 100

What is the number of valence electrons in the atoms of an element having atomic number 13? Name the valence shell of this atom.

Important Questions on Structure of Atom

MEDIUM
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 33
What are isotopes? Explain by giving an example.
MEDIUM
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 33
Give one similarity and one difference between a pair of isotopes.
HARD
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 33
Give the number of protons, neutrons and electrons per atom in the two isotopes of chlorine Cl1735 and Cl1737. 
HARD
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 34
What are radioactive isotopes? Give two examples of radioactive isotopes.
MEDIUM
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 34
Give any two uses of radioactive isotopes.
HARD
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 34
An element Z contains two naturally occurring isotopes Z1735 and Z1737. If the average atomic mass of this element be 35.5 u, calculate the percentage of two isotopes.
MEDIUM
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 35
Define valency of an element. What valency will be shown by an element having atomic number 14?
HARD
9th CBSE
IMPORTANT
Science for Ninth class Part 2 Chemistry>Chapter 4 - Structure of Atom>Long Answer Type Questions>Q 35
What is the relation between the valency of an element and the number of valence electrons in its atoms? Explain with examples.