Answer:
Even in a chemical reaction when atoms interact and create new products, mass is conserved. This is because the new substances created are composed of atoms that were present in the reactants. The atoms from the reactants come apart, rearrange, and re-bond in a different arrangement to form the products.
All organisms are made of cells
all existing cells are produced by other living cells
the cell is the most basic unit of life
Answer: Option (C)
Explanation: The rocks at the continental crust are present since a long time, and the oldest rocks so far encountered from the continental crust is approximately 4.4 billion years old.
This has been determined by the Uranium-Lead dating method (Ur₂₃₈-Pb₂₀₆).
Oceanic rocks are estimated to be of very recent age i.e about only 180 million years old.
Answer:
The magnitude of the magnetic field is 0.156 T.
Explanation:
Given that,
Speed of a proton, 
Radius of the circular path, r = 0.2 m
When the proton enters in the circular path, the centripetal force is balanced by the magnetic force such that :
q is the charge on proton
Here, 
So, the magnitude of the magnetic field is 0.156 T. Hence, this is the required solution.
