Answer: The atoms of the solid products are tightly packed whereas those in gas are loose.
Explanation:
Atoms in the solid structure are linked to each other by strong force of attraction and they collectively form an three-dimensional structure. The binding of the atoms form the shape of the solid product. The gas exhibit free atoms in it. The atoms are not linked to one another by strong force of attraction. The atoms as a part of gas have higher energy as those present in the solid products. So, the atoms of the gas wander freely as compared to those in the solid products.
The answer to the question is radium (Ra)
It's called a compound because different elements are held together by a chemical bond.
To determine what gas is this, we use Graham's Law of Effusion where it relates the rates of effusion of gases and their molar masses. We do as follows:
r1/r2 = √(M2 / M1)
Let 1 be the the unkown gas and 2 the H2 gas.
r1/r2 = 0.225
M2 = 2.02 g/mol
0.225 = √(2.02 / M1)
M1 = 39.90 g/mol
From the periodic table of elements, most likely, the gas is argon.