Base on my research, within 2 hours you have a number of atoms which remain.
N= N0*2^(-t/6.020 = N= N0*2^-0.33223= 07943 N0
So, the number of atoms that are being disintegrated is N0-N=N0*(1-0.79430)=0.2057 N0
It must be equal to 15 mCi = 15*3.7*10^7= 5.55*10^8 atoms
N0= 5.55*10*8/0.2057 = 2.698*10^9 atoms
Therefore, 2.698*10^9 atoms is the number of N0
The Electric field is E=23400 V/m.
What is electric potential ?
The amount of labor required to convey a unit of electric charge from a reference point to a given place in an electric field is known as the electric potential (also known as the electric field potential, potential drop, or the electrostatic potential). More specifically, it is the energy per unit charge for a test charge that is negligibly disruptive to the field under discussion.
The electric field of a spherical conductor is given by:

Here 'E' is the electric field and 'Q' is the electric charge.
therefore putting the values we get,
E=23400 V/m
To learn more about electric field click on the link below:
brainly.com/question/11509296
#SPJ4
FACT: An organism's kingdom does not only describe physical characteristics.
Organisms are classified into the different kingdoms based on physical appearance, their function, how they reproduce and how they obtain their food.
EVIDENCE:
Kingdom Plantae: They obtain their food through photosynthesis
Reproduce asexually.
Kingdom Animalia : They obtain their food through hunting or consuming other organisms.
Reproduce sexually.
Answer:
Explanation:
Initially no of atoms of A = N₀(A)
Initially no of atoms of B = N₀(B)
5 X N₀(A) = N₀(B)
N = N₀ 
N is no of atoms after time t , λ is decay constant and t is time .
For A
N(A) = N(A)₀ 
For B
N(B) = N(B)₀ 
N(A) = N(B) , for t = 2 h
N(A)₀
= N(B)₀ 
N(A)₀
= 5 x N₀(A) 
= 5 
= 5 
half life = .693 / λ
For A
.77 = .693 / λ₁
λ₁ = .9 h⁻¹
= 5 
Putting t = 2 h , λ₁ = .9 h⁻¹
= 5 
= 30.25
2 x λ₂ = 3.41
λ₂ = 1.7047
Half life of B = .693 / 1.7047
= .4065 hours .
= .41 hours .