It's seven times saltier than the ocean, making swimmers super-buoyant. The Dead Sea is really a lake with no outlet. What make sit so salty? In the hot climate the water evaporates, leaving a load of salt behind. It's called 'dead' because fish can't live in its super-salty waters.

Condensation

Molecules of water vapor in the air are so small you cannot see them. For a person to be able to see an object, light must strike the object, which then reflects, or bends, the light back toward a person's eyes. Water molecules are so small that they do not bend back enough light for us to see. As water molecules combine, they form water droplets. For a water droplet to be visible it must contain about 10 billion molecules of water.

When water vapor rises into the atmosphere high above the earth's surface and meets cooler air, it can change in two ways. One way the vapor may change is by turning into water droplets. But if the air temperature is very cold, deposition-the change of water vapor directly into solid ice crystals-may occur. Deposition also takes place on the ground. Frost is an example of water vapor that has gone through deposition, changing from a vapor into a solid without first becoming liquid water.

During warm months, the sun heats the air. But the high air temperatures often fall at night after the sun goes down. In the early morning, blades of grass may be coated with water droplets, or dew, the result of cooler night air temperatures. (Remember, cool air holds less water than warm air.) When water vapor condenses, dew forms on surfaces. As the air cools, it reaches a point, called the dew point, at which it is saturated with water vapor. Condensation begins at the dew point because the air is saturated and cannot hold any more water.

As water vapor high in the atmosphere cools to the dew point, it condenses around dust particles, forming droplets. The droplets come together in larger and larger clumps until they are big enough to reflect light for us to see. These visible clumps of water droplets and if the air temperature is cold enough, ice crystals-are called clouds.
Millions of water droplets and ice crystals combine to form the large clouds we see in the sky. The cottony clouds that look so fluffy and light actually contain enough water droplets and ice crystals to weigh half a million tons. The enormous black clouds of a thunderstorm may weigh several million tons! When water droplets and ice crystals become too heavy for air currents to hold them suspended in the atmosphere, they fall toward the earth as precipitation.

Although clouds can contain enough water to weigh millions of tons, the total amount of water contained in all the clouds at any one time is actually less than .001 of I percent of the earth's water supply. If suddenly all the water droplets, ice crystals, and vapor contained in clouds and the atmosphere were to condense and fall evenly over the earth's surface, the total amount would only measure about 1 inch (2.54 cm) of rain.

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