Answer:
Experimental investigations are the best type of scientific research to demonstrate the relationships between cause and effect because they allow the investigator to actively manipulate variables and control conditions. This change can be measured to gather evidence to back up or refute the relationship between cause and effect.
B is true since evaporation changes a liquid into a gas and dondensation turns a gas into a liquid
The complete chemical reaction of aqueous Sodium sulfate and aqueous Barium nitrate is

The right side and the left side of the reaction have equal number of elements, therefore it is balanced.
The answer will be A.
Sorry if it was incorrect but that’s the closest answer.
<u>Answer:</u>
2.0158 grams
<u>Explantion:</u>
We are to find the mass of the hydrogen atoms in 1 mole of water.
We know that the formula of water is: 
We can see, from the above mentioned formula, that water has 2 hydrpgen atoms.
From the periodic table, we get to know that Hydrogen has an atomic mass of 1.00794 grams.
As there are 2 atoms of hydrogen in water so
grams is the answer