Answer : 
Explanation :
Given that
Radius of sphere 
The distance between the centers of the two spheres is

The charge of the sphere 
The magnitude of the repulsive force between the charges pushing them a part is
Using coulomb law




Hence, this is the required solution.
Answer:41.991ml
Explanation:
Equations: 2 H2O → 4H+ + 4e + O2 OXIDATION
2 H+ + 2e → H2 REDUCTION
Electrolysis is the chemical decomposition of compounds when electricity is made to pass through a molten compound or solution.
from the oxidation reaction:
1moles of oxygen requires 4moles of electrons to be discharged at the product
F=96500C/mol
Quantity of charge Q=It
=60*60*0.201A
Q=723.6C
Mole=Q/(F*mole ratio of electron)
Mole= 723.6/(4*96500)
Mole=((1809)/(965000))
M=0.0018746114
M1/M2=V1/V2
1/0.00187=22.4dm^3/V2
V2=22.4*0.00187
V2=0.04199129534dm^3
41.99129534ml
Answer:
6 days.
Explanation:
From radioactivity, The expression for half life is given as,
R/R' = 2⁽ᵃ/ᵇ)................... Equation 1
Where R = original mass of the radioactive substance, R' = Remaining mass of the radioactive substance after decay, a = Total time taken to decay, b = half life.
Given: R = 80 g, R' = 10 g, b = 2 days.
Substitute into equation 1
80/10 = 2⁽ᵃ/²⁾
8 = 2⁽ᵃ/²⁾
2³ = 2⁽ᵃ/²)
Equating the base and solving for a
3 = a/2
a = 2×3
a = 6 days.