Hydroxide ions (OH-) consist of one oxygen atom bonded to one hydrogen atom carrying a negative charge overall due to presence of extra electron.
Substances that donate hydroxide ions when dissolved in water.
Alkalinity: The capacity of water to neutralize acids, which is related to its hydroxide ion concentration.
Amphoteric Substance: A substance, like water, that can act as both an acid (donating H+ ions) and a base (donating OH- ions).