Question: a. the teacher puts a sugar cube into a container of warm water. eventually the sugar cube is no longer visible. what type of change is this and why?

physical change.

Explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.  Example: melting of ice

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.  Example: Combustion

As the sugar cubes dissolves into a container of warm water, it only changes its state from solid to aqueous and no new substances are being formed. Thus it is a physical change.

the endomembrane system is a series of compartments that work together to package, label, and ship proteins and molecules. in your cells, the endomembrane system is made up of both the endoplasmic reticulum and the golgi apparatus. these compartments are folds of membranes that form tubes and sacs in your cells.

i'd say that the moon rock is about 2.2 billion years old.