Answer:
13.98 nC
Explanation:
Capacitance depends upon the area of the plates and their distance of separation.
Radius = r = 0.071 m
separation = d = 0.00126 m
here κ = 1 and ε₀ = 8.85 ₓ 10⁻¹² SI units , for free space.
Area = A = π r² = 0.0158 m²
C = [( 8.85 ₓ 10⁻¹² ) ( 0.0158) ]÷ (0.00126) = 1.11 x 10⁻¹⁰ F
Charge = Q = C V = ( 1.11 x 10⁻¹⁰ F )(126) = 13.98 nC
= 14 nC ( rounded to two significant digits)
Answer: a) 3.85 days
b) 10.54 days
Explanation:-
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = ?
t = time taken for decomposition = 3 days
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process =
First we have to calculate the rate constant, we use the formula :
Now put all the given values in above equation, we get
a) Half-life of radon-222:
Thus half-life of radon-222 is 3.85 days.
b) Time taken for the sample to decay to 15% of its original amount:
where,
k = rate constant =
t = time taken for decomposition = ?
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process =
Thus it will take 10.54 days for the sample to decay to 15% of its original amount.