The answer is:
C.Their densities are lower than the density of water.
The Explanation:
According to the table below of the density of alkynes you will see that it is lower than the density of water. densities of alkenes , alkynes and aromatic hydrocarbons are lower than the water.
and the alkenes are insoluble in water because it has a non polar characteristics and it is also lighter than water because its density is lower than water.
An acid base reaction occurs since we know that vinagar is just acetic acid and baking soda is just sodium bicarbonate. The vinagar (weak acid) is going to react with the bicarbonate (weak base) to create carbonic acid which decomposes into carbon dioxide and water. I hope this helps. Let me know in the comments if anything is unclear.
Yes the water boils but it doesn't become water gas it becomes just gas also known as evaporation
The answer is A. Fusion splits atoms.