Helium is stable compound. exists in gaseous state. the answer is gas
The correct answer is elements in family 7 have similar properties because elements in the same group or family have the same number of valence electrons.
<h3>Further explanation</h3>
Given
the structure of the alkanes
Required
match the image to the name
Solution
Alkanes are saturated hydrocarbons with all of the carbon bonds being single bonds
General formula:

If we look at the picture, we define the black atom as Carbon and the branch is Hydrogen
To determine the name of the alkane, all we have to do is count the number of Carbon atoms
Butane : C₄H₁₀ : 4 C atoms
Methane : CH₄ : 1 C atom
Ethane : C₂H₆ : 2 C atoms
Propane : C₃H₈ : 3 C atoms