Which of the following is an example of a longitudinal wave

Examples of longitudinal waves include: sound waves. ultrasound waves. seismic P-waves.

D. Sound waves

Explanation:

The following options are missing:

A. radio wave

B. X-rays

C. Light waves

D. Sound waves

There are two kinds of waves: longitudinal and transverse.

In longitudinal waves, the vibrations are parallel to the direction of wave travel. Examples of longitudinal waves include: sound waves  and ultrasound waves.

In transverse waves, the vibrations are at right angles to the direction of wave travel. All electromagnetic waves (e.g. light waves, microwaves, radio waves and X-rays) are transverse waves.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.