c.diamonds are the hardest
Answer:
Geosphere and Hydrosphere.
Explanation:
Hot springs are heated by geothermal heat—heat from the Earth's interior. In volcanic areas, water may come into contact with very hot rock heated by magma. The geosphere and hydrosphere interact when hot springs form. The geosphere gets a little melted by the hot hydrosphere and then when the springs shoot up in the air they break some rocks.
Solution :
According to the Graham's law of diffusion, we know that, the rate of the diffusion varies inversely to the molar mass of the gas, i.e.
Rate of diffusion, 
where, the 'M' is the molar mass of the gas.
Now in the case of the isotopes of the Krypton,
Atomic mass of
= 80 AMU
Atomic mass of
= 82 AMU
Atomic mass of
= 83 AMU
So the ratio of the rate of diffusion of the three isotopes are :



Dividing the above three with the smallest number among the three i.e. 0.10976, we get the relative rates of diffusion.
∴ 
= 1.02 : 1.01 : 1
Hence the relative rate of diffusion are :

Hi There!
Obsidian - Igneous Rock
Marble - Metamorphic Rock
Conglomentary - Sedimentary Rock
Hope This Helps :)
Mg is what you measure them in