The speed of an object traveling below the speed of sound is called infrasound subsonic ultrasound supersonic

The speed of an object traveling below the speed of sound is called Subsonic .

Explanation:

Infrasound: These are the sound waves with frequency less than the 20 hertz.Sound waves with lower frequencies which are below the lower limit of human audibility.

Subsonic : Speed of an object less than the speed of sound with sound propagating medium..

Ultrasound : These are the sound waves with frequency upper than the 20,000 hertz.Sound waves with higher frequencies which are above the upper limit of human audibility.

Supersonic : Speed of an object greater than that of the speed of sound.

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.