Answer:
Absolute error 
% Error
5
Explanation:
The absolute error is the the difference in the measured value and the actual value of a quantity.
Here the actual value is
grams
The measured value is
grams
Absolute error

Percent error

Where AE stands for absolute error and AV stands for absolute value.

%
Answer:
Atom - un átomo de hidrógeno pierde un electrón, adquiere una carga positiva
Molecule - Al aumentar el calor, las moléculas se alejan en mayor medida unas de otras y se intensifica su estado de agitación.
I think its B but im not sure...
1.66x10^-15 mol. It's not a full mole. You take the number of molecules and use dimensional analysis to figure it out.
Answer: Pure substances cannot be separated by physical means.
Explanation:
A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means.
On the other hand, a mixture is a substance which contains two or more than two types of components and they can be separated by physical means as well.
Thus, option (a) is correct one that is pure substances cannot be separated by physical means.