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
I believe the answer is b) slowly heating the surface
Answer:
Circuit 1 and Circuit 3
Explanation:
If there is 1 Circuit and it runs out of energy, there's another one to produce the power.
We know that According to Ohm's Law :
Current passing through a Conductor is directly proportional to the Voltage over a given Resistance.
⇒ V ∝ I
⇒ V = I × R
If Resistance is not changed and Voltage is increased, Based on Ohm's law we can conclude that Current flowing will also increase, because Voltage is directly proportional to Current.