Answer: 3.67 x 10^24
Explanation: 1mole of Cr contains 6.02x10^23 atoms
Therefore 6.098moles of Cr will contain = 6.098 x 6.02x10^23 = 3.67 x 10^24
Answer:
I found on internet may be it helps
Explanation:
Here, we provide a general review of recent studies into the genetic basis of human brain evolution. The insights gleaned from these studies can be broadly divided into three categories: (i) positive selection on protein-coding regions of the genome that lead to changes in the sequences of existing proteins; (ii) duplication and deletion of genes; and (iii) evolutionary changes in non-coding regions of the genome, especially those in cis-regulatory sequences that lead to altered gene expression .
Density = mass/volume = 316/22.5 = 14.045g/mL.
The first one is wrong
2.67 cm= 1.051 inches
Answer:
It takes 178.4 years to drop the activity from 15.0 Ci to 0.25 Ci
Explanation:
Step 1: Data given
Half-life time = 30.2 years
Initial activity = 15.0 Ci
Final activity = 0.250 Ci
Step 2: Calculate the time needed
N / No = e^(-0.693 * t / T1/2)
⇒ with N = The activity after dropped = 0.250 Ci
⇒ with N0 = the initial activity = 15.0
⇒ with t= the time (in years) needed to drop the activity from 15.0 to 0.250
⇒ with t1/2 = the half- life time is 30.2 years
0.250 / 15.0 = e^(-0.693 * t / 30.2)
ln(0.250/15.0) = (-0.693 * t / 30.2)
-4.09 * 30.2 = -0.693t
-123.65 = -0.693t
t= 178.4 years
It takes 178.4 years to drop the activity from 15.0 Ci to 0.25 Ci