Many of these microscopic organisms are , or unicellular. many-celled

one-celled

dual-celled

triple-celled

One-celled.

Many of these microscopic organisms are one-celled or unicellular.

I hope this helped at all.

The correct answer is C. In the periodic table nitrogen has 5 valence electrons and needs 3 more electrons to obtain an octet. So it would form three covalent bonds with another nitrogen and that would be a triple bond.

A is incorrect because oxygen is in group 6 and only needs 2 electrons to achieve an octet. So it would form two covalent bonds with the other oxygen to give a double bond.

B is incorrect because Cl is in group 7 and only needs 1 electron to achieve an octet. So it forms a single bond with the other Cl atom.

D is incorrect because helium is in Group 8, a noble gas, which means its valence shell is completely filled, hence no bonding can occur.