EASY
Earn 100

What is the main difference among the isotopes of the same element?

Important Questions on Structure of The Atom

HARD
The half-life of a radioisotope is 4 hours. If the initial mass of the isotope was 200 g, the mass remaining after 24 hours undecayed
MEDIUM

Two atoms are said to be isobars if 

EASY
Hydrogen contains three types of atoms (H11 protium, H12 deuterium, H13 tritium). These atoms are
EASY
An isotope of which element is used in the treatment of cancer?
MEDIUM
Which one of the following is cation 
HARD

Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15  of the Periodic Table. Write the electronic configuration of these two elements. Which one of these will be more electronegative? Why? 

MEDIUM

The following is the correct decreasing order of the ionic radii- 

EASY
The number of protons in one atom of an element X is 8. What will be the number of electrons in its ion X-2?
EASY
Radioactive isotope used in the treatment of cancer disease is 
EASY
Which statement out of the following is true? Isobars have
MEDIUM
Two elements P and Q have 5 and 7 electrons in their outermost shell respectively. The atomic number of P and Q will be
MEDIUM
An atom has electronic configuration 2, 8. 7. What is the atomic number of this element.
EASY
In the formation of which of the following compounds, the octet rule is not obeyed?
EASY
Which of the following elements has two shells, both of which are completely filled with electrons? 
EASY

Give one phrase for the following statement:

Process of formation of ions from molecules which are not in the ionic state.