Answer:
1. The standard metric unit of length is a meter.
2. A proposed explanation for a scientific problem is a hypothesis.
3. The standard unit of volume is a liter.
4. The curved top surface of a liquid column is the meniscus.
5. A quantity in an experiment that remains unchanges or constant is a controlled variable (control)
6. The amount of matter in an object is mass.
Answer:
Theoretical yield of vanadium = 1.6 moles
Explanation:
Moles of 
= 1.0 moles
Moles of 
= 4.0 moles
According to the given reaction:-
1 mole of react with 5 moles of
Moles of Ca available = 4.0 moles
Limiting reagent is the one which is present in small amount. Thus, Ca is limiting reagent. (4.0 < 5)
The formation of the product is governed by the limiting reagent. So,
5 moles of Ca on reaction forms 2 moles of V
1 mole of Ca on reaction for 2/5 mole of V
4.0 mole of Ca on reaction for 
mole of V
Moles of V = 1.6 moles
<u>Theoretical yield of vanadium = 1.6 moles</u>
<span>Hydroelectric energy uses the movement of water to spin a turbine and produce electricity. Coal is a fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways. Coal use is more common than the use of hydroelectric energy.</span>
