These are singular, relatively long, whip-like organelles that many unicellular organisms use for motion.

Flagellum

Explanation:

Flagellum are singular organelles located at the caudal end of cells, mostly bacteria that are used to propel the organism in a specific direction. These are relatively long to the size of the organism, usually it's around the same size as the cell's body.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.