Answer:
20 g/mol
Explanation:
We can use <em>Graham’s Law of diffusion</em>:
The rate of diffusion (<em>r</em>) of a gas is inversely proportional to the square root of its molar mass (<em>M</em>).

If you have two gases, the ratio of their rates of diffusion is

Squaring both sides, we get

Solve for <em>M</em>₂:



Given mass of Scandium = 50.0 g
Increase in temperature of the metal when heated = 
Heat absorbed by Scandium = 
The equation showing the relationship between heat, mass, specific heat and temperature change:

Where Q is heat = 
m is mass = 50.0 g
ΔT = 
On plugging in the values and solving for C(specific heat) we get,
=50.0g(C)(
)
C = 0.491
Specific heat of the metal = 0.491
Answer:
a
Explanation
Bc I took the test, good luck with that guys