In physics and chemistry, we talk of viscosity and density of liquids and gases. What do these words mean?
Viscosity is measure of resistance of liquids to flow. The friction between the layers of the liquid or fluid may allow it to flow easily or less easily. Liquids that flow easily are said to be less viscous for example water. The molecular bonds are weak in this case. This means the the resistance between the water molecules are minimal thus making it less viscous. A more viscous liquid is less able to flow for example oil has a lot of resistance within its molecule layers.
Density is the measure amount of matter which is mass divided by the space that matter occupies which is volume.in other words it is the mass per volume unit.
Viscosity and density are often confused but are completely different concepts.in case of water, we may measure its viscosity and identify it is less viscous because of the loose molecular bonds. The density of water may be measured and found to be 0.1g/ml.