Answer:- 
Explanations:- Alkanes are non polar molecules as these only have carbons and hydrogens. Electron negativity difference of C and H is very low and it makes them non polar. These have weaker London dispersion forces.
The forces of attraction becomes stronger in alkanes as the number of carbon increases because the surface area as well as molecular weight of the alkanes increases with an increase in number of carbons.
Butane has four carbons, propane has three carbons, ethane has two and methane has only one carbon, So, the strongest to weakest order of inter molecular forces is butane > propane > ethane > methane .
D will be the answer I hope that help good luck I hope. My answer help you
Answer: Option D) covalent bonds between water molecules
In water, hydrogen bonds are best described as covalent bonds between water molecules
Explanation:
The hydrogen bonds between water molecules are covalent bonds because they are formed when oxygen attract the lone electron in hydrogen, thus resulting in the formation of a partially negative charge on the oxygen atom and a partially positive charge on two hydrogen atoms
Thus, the sharing of electrons between oxygen and hydrogen atoms is responsible for the covalent bonds between water molecules
The first three quantum numbers for electrons located in subshell 4s are :
Always use least amount of sig figs possible. So this 9.7 would be (answer): 2 sig figs
