Litmus strips
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The pH level of a solution is determined by the amount of positive hydrogen ions and negative hydroxide ions present. Acids have a low pH, bases a higher pH. Typically, when an acid and a base are combined, water and a salt are formed.

pH Level

pH test
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The pH level is also known as the potential of hydrogen level. It’s the measure of acidity or alkalinity of a solution. The higher the number of positive hydrogen ions, the lower the pH.

Acids

Fresh made Grapefruit Juice
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Acids, with their large amount of hydrogen ions, have an acidic, or sour, taste. Vinegar and grapefruit juice are two harmless acids. Hydrochloric acid is much more dangerous and may cause severe burns.

Bases

Antibacterial Soap Dispenser
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Bases, or alkaline solutions, have a greater number of negative hydroxide ions. They have a slippery feel, like soap does, and are also characterized by a bitter taste. The addition of a base will decrease the acidity of a solution.

Salts

Spilled Salt
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Salts and water are formed when an acid and base are combined and neutralized. The negative ions of the base and the acid form water and the positive ions form a salt compound.

Homeostasis

Alkaline Testing
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The body has a pH that is between 7.35 and 7.45. This nearly neutral pH is desired to keep cells functioning properly. The body regulates its own pH level constantly, keeping it within normal range, in a process called homeostasis.