Answer:
The mass of Uranium present in a 1.2mg sample is 
Explanation:
The ration between Uranium mass and total sample mass is:
For a sample of mass 1.2 mg, the amount of uranium is:

Answer:
8.0s
Explanation:
45 km/h ÷ 3.6 = 12.5 m/s
t.v = d/t
vt/v = d/v
t = d/v = 100.0m /12.5 m/s = 8.0s
Hope this helps!!
As we know that speed of sounds is given as

here we know that
t = 23 degree C
now from above equation we will have


now we also know that distance between two consecutive resonance length is half of the wavelength



now we know that


so frequency will be 786 Hz
A non-reversible Acton. A chemical reaction in non-reversible