Half of the moon is illuminated.
Answer:
option A
Explanation:
The correct answer is option A
The binary star system is the system in which two stars are continuously orbiting each other,
In the eclipsing binary system, two stars revolve about there center of mass and in this system one one-star eclipse another star.
Spectroscopic binary stars are found from the observation of radial velocity and the brighter member of such binary can be seen to have continuously changed the wavelength and periodic velocity.
When the pairs of stars appear to change position in the sky then it is known as visual binary.
Answer: a) 
b) 
Explanation:
A nuclear fission reaction is defined as the reaction in which a heavy nucleus splits into small nuclei along with release of energy.
a) The given reaction is 
Now, as the mass on both reactant and product side must be equal:


Thus three neutrons are produced and nuclear equation will be: 
b) For the another fission reaction:

To calculate A:
Total mass on reactant side = total mass on product side
235 + 1 = A + 94 + 2
A = 140
To calculate Z:
Total atomic number on reactant side = total atomic number on product side
92 + 0 = 56 + Z + 0
Z = 36
As Krypton has atomic number of 36,Thus the nuclear equation will be :
