Answer:
Measuring with a ruler and using final volume minus initial volume
Explanation:
You can measure the volume of a geometric object by measuring its sides with a ruler and calculating the volume according to the corresponding formula for each object. For example, for a rectangular prism it would be

You can also measure the volume of an object by measuring how much water it displaces. To do this you have to fill a measuring cylinder with enough water for the object to be completely submerged and take note of the volume. Then, add the object and note again the volume of the water+object. The difference between both is the volume of the object.

The advantage of the second method is that it can be used for objects with irregular shapes as long as they do not float.
About 6.5x10^22 molecules.
(5g C2H5OH)x(1 mol C2H5OH/46g C2H5OH)x(6.02x10^23 molecules C2H5OH/1 mol C2H5OH)=(3.01E24)/46=6.5x10^22.
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Answer:
sodium chloride—is NaCl.
Explanation:
Table salt is an ionic compound, which breaks into its component ions or dissociates in water. These ions are Na+ and Cl-. The sodium and chlorine atoms are present in equal amounts (1:1 ratio), arranged to form a cubic crystal lattice.
Answer:
2H₂ + O₂ → 2H₂O
Explanation:
The expression of the equation is given as:
_H₂ + 2O₂ → 2H₂O
Now for expression above,
Reactants Products
H 2 4
O 4 2
to balance the equation, we use 2 moles of hydrogen gas and 1 mole of oxygen gas;
2H₂ + O₂ → 2H₂O