defence exam ITBP (Telecommunication) Head Constable Mock Test 2024 General Science Chemistry Chemical Reaction
Consider the following aspects of substances involved in a chemical reaction:
A. Physical state of all the substances
B. Number of molecules of all substances
C. Number of atoms of each substance
D. Sum of masses of all atoms of substances
Which of the above remain the same before and after a chemical reaction has taken place?
1
A and B
2
B and C
3
C and D
4
A and D