I would say D, because you need to start with nothing to measure the different sizes as they start to grow. hope this helps!
Answer:
open system
Coffee held in a cup is an open system because it can exchange matter water vapors and energy heat with the surroundings.
Answer: spring tides
When earth, moon, and sun line up cause high and low tides :)
2 × (atomic mass of Ag) + (atomic mass of Cl (