Answer:
It s a pure substance.
Explanation:
Can only be separated into its different elements by chemical means because it is connected by a chemical bond.
(1,0)n +(235,92)U --->(91,36)Kr + (142,56) Ba + 3(1,0)n
The mass of a chemical substance is known as the atomic number or atomic mass
The molecular weight of unknown gas : 23.46 g/mol
<h3>Further explanation</h3>
Given
A vessel contains 10% of oxygen and 90% of an unknown gas.
diffuses rate of mixed gas = 86 s
diffuses rate of O₂ = 75 s
Required
the molecular weight of unknown gas (M)
Solution
The molecular weight of mixed gas :(M O₂=32 g/mol)

Graham's Law :
