There are two identical copies of the original DNA.
The existence of liquids is the most important component of intermolecular forces.
In liquids, we can see several other manifestations of intermolecular forces.
A fly fisherman delicately casts a small fishing fly (a metal hook with a few feathers and strings attached to make it look like an insect) onto the surface of a moving stream.
The fly floats on the surface of the water, even though the hook is denser than water.
Liquids, Solids, and Intermolecular Forces recall from Section 12.3 that the Surface molecule interactions between molecule interacts with only lower their potential energy in four neighbors.
The liquid surface has a higher potential energy than the interior.
The figure shows the intermolecular forces experienced by a molecule at the surface of the liquid compared to those experienced by a molecule in the interior.
The molecule at the surface is inherently less stable than those in the interior because it has fewer neighbors to interact with.
In order to increase the surface area of the liquid, molecules from the interior have to be moved to the surface, and because they have a higher potential energy than those in the interior, this movement requires energy.
Liquids tend to have less surface area.
A paper clip floats on water with a surface tension of 72.8 mJ, it takes 72.8 mJ to increase the sur.
A kind of skin at the surface that resists penetration is created by the ten dency for liquids.
The water's surface area must increase slightly in order for the fisherman's hook to sink into the water.
We can see surface tension by placing a paper clip on the water's surface.
The paper clip floats on the surface of the water even though it is denser than water.
A small tap on the clip causes the clip to sink.
Intermolecular forces decrease as surface tension decreases.
Water droplets are not water.
The reason for the behavior of water is due to surface tension, and we discussed it in nearly perfect spheres.
You can see this behavior on Earth by looking at small water droplets that are not large enough to be distorted by gravity.
Smaller samples of water form spheres in the space station.
In the same way that gravity pulls the matter of a planet inward to form a sphere, intermolecular forces pull the water into a sphere.
The formation of a sphere with the smallest ratio of surface area to volume reduces the potential energy of the system.
Motor oil is more elastic than gasoline and maple syrup is more elastic than water.
The P is defined as 1 g> cm # s.
One centipoise is the Viscosity of water at room temperature.
The stronger the intermolecular forces, the greater the Viscosity is.
Increasing in longer molecules that can interact over a greater area can cause Viscosity to increase.
There are several hydrocarbons listed in Table 12.5.
Notice the increase in viscosity with increasing molar mass and with increasing length.
The intermolecular forces are partially overcome by thermal energy, which allows the molecule to flow past each other more easily.
The table shows how the temperature affects the water's viscosity.
As temperature increases, nearly all liquids become less viscous.
The result is an oil that is less temperature dependent than it would be otherwise, allowing Viscosity to be an important property of the motor oil you put into your car.
The oil must be thick enough to coat engine surfaces and thin enough to be used over a wide range of temperatures.
It will be easy to get into all the required engine compartments.
The 10W-40 designation indicates that the oil has a rating of 40 on the SAE scale.
The thinnest motor oils have a rating of 5 or 10, while the thickest has a rating of up to 50.
Before the 1950s, owners of cars had to change the oil in their engines in the summer if they wanted a higher rating in the winter.
Multi grade oils allow car owners in many climates to keep the same oil all year long.
The 10W-40 oil shown at right is a multi grade of oil that has long molecule that coil at low temperatures but then break down at high temperatures.
The coiled polymers do not contribute much to the oil's viscosity at low temperatures.
When taking a blood sample, a liquid can flow up a narrow tube.