11Most of the Earth’s water is salt water Most of the Earth’s water is salt water. It cover two-thirds or our planet’s surface.
12The Pacific Ocean is Earth’s largest ocean The Pacific Ocean is Earth’s largest ocean. It is so big that all of Earth’s land could fit inside it.
13Where does most of the salt water on Earth come from? Weathered rocks
14Ocean water is too salty to drink Ocean water is too salty to drink. The salt in ocean water is greater than the concentration of salt in human body tissues. Drinking ocean water leads to unhealthful dehydration and more thirst.
15Dehydration is a dangerous lack of water in the body.
23Water can be found in various forms Gas as in water vapor.Liquid as waterSolid as ice.
24Water vapor in air can also freeze as it condenses, to form frost Water vapor in air can also freeze as it condenses, to form frost. Air must be cold for frost to form.
25Frost is seen in the morning because air temperature drops overnight.
26Water Treatment PlantWater treatment plants treat water or filters water from rivers or lakes. They also filter some water that has been used. Water treatment plants clean the water before human consumption.
27Filter means to clean dirt, chemicals, and bacteria from the water.