Well you see unicellular organisms are very unique in the fact that they live all on their own and move around with a flagellum or little motor, but to the point unicellular organisms carry out essentially every function in life and they must in order to simply survive. So it's most likely D.
Answer:
A: Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions. It is likely to react with an element with six valence electrons that “wants” to gain two electrons. This would be an element in group 6, such as oxygen.
There is 1 atom of Al
(And 3 of Cl)
