Explanation:
a ...15 seconds×(3600 seconds hour)
Answer:
OPTION (A) : Testing a rock sample for gold content
Explanation:
For testing a rock sample of gold content you will need a Chemist. To test the material, the sample is rubbed on black stone which will leave a mark on the stone. This mark is tested by applying aqua fortis i.e nitric acid on the mark. If the mark gets dissolve then the material is not gold. If the mark sustain the it is further tested by applying aqua regia i.e nitric acid and hydrochloric acid which will prove the sample is of gold if it gets dissolve on using hydrochloric acid. The purity of the sample can be checked by differing the concentration of the aqua regia and comparing it with the gold material of the known purity.
Answer:
If the half-life of 14C is 5730 years, when this period of time has passed it will have been halved, it is called the exponential decay law of radioactive isotopes.
I believe that the choices for this question are:
C2H4O2, C4H8O4 CH2O, C6H12O6 C3H6O3, C6H12O6 C2H4O2, C6H12O6
The answer to this based on the molar masses given is:
C2H4O2, C6H12O6
To prove calculate the molar mass:
C2H4O2 = 2*12 + 4*1 + 2*16 = 60
C6H12O6 = 6*12 + 12*1 + 6*16 = 180
1 km is equal to 100,000 cm
and you need to divide it to 1 km so that you can get rid of the km.
