Tetanus vaccine can help prevent tetanus disease, commonly known as lockjaw.. Tetanus is a serious disease that causes painful tightening of the muscles, usually all over the body. It can lead to locking of the jaw so the person cannot open his mouth or swallow. Tetanus leads to death in about one in ten cases.
The most abundant dissolved salt in ocean water is sodium chloride. It is a colorless crystalline compound with the chemical formula of NaCl.
But why is the ocean salty? Ocean water contains lots of different mineral salts: sodium, chloride, sulfate, magnesium, calcium, potassium, bicarbonate and bromide. These salts enter the ocean through rivers, which pass over rocks and soil, picking up salt along the way. This salt builds up in the ocean because the only way water can leave the ocean is through evaporation. And when the water evaporates it doesn't take the salt with it. So you end up with less water, and the same amount of salt, resulting in a pretty salty sea.