Sound needs medium to travel and it can not travel without medium
so sound wave is a travelling wave
now we also know that sound wave propagate in form of rarefaction and compression.
So all medium particles travel in the direction of wave only
so it is a longitudinal wave also
so correct answer will be
<em>mechanical longitudinal </em>
Low levels of fecal coliform
Answer:
High boiling and melting points: Hydrogen bonds increase the amount of energy required for phase changes to occur, thereby raising the boiling and melting points.
High specific heat: Hydrogen bonds increase the amount of energy required for molecules to increase in speed, thereby raising the specific heat.
Lower density as a solid than as a liquid: Hydrogen bonds increase the volume of the solid by holding molecules apart, thereby decreasing the density
High surface tension: Hydrogen bonds produce strong intermolecular attractions, which increase surface tension
Explanation:
Once all hydrogen is depleted the star begins to die
