Answer:
3 hydrogen bonds.
Explanation:
This is because the urea molecule has an oxygen atom bound with double bonds to the central carbon atom, and this oxygen can form a hydrogen bond with water, as well as both terminal amine groups that can also form a hydrogen bond each because of the lone pair of electrons on the nitrogen group.
I don't know what model you're referring to so I can't answer the question. However, upon researching, I found a similar problem. I posted it as an attached picture. Looking at the model, the amount of grams a herbivore eat each day corresponds to the arrow pointing inwards. Since the label says 4.0 g,
<em>the answer is 4 g per day</em>.
2KBrO₃(s) = 2KBr(s) + 3O₂(g)
Oxygen gas is formed.
This food supplement E924 is banned in some countries.
Answer:

Explanation:
The given reactions are:
PbCl2(aq)⇌Pb2+(aq)+2Cl−(aq) 
AgCl(aq)⇌Ag+(aq)+Cl−(aq) 
Required reaction is:
PbCl2(aq)+2Ag+(aq)⇌2AgCl(aq)+Pb2+(aq)

This is a false statement. Graduated cylinders measure volume, yes, but i'm afraid that beakers do not.
Hope this helps!