Alkalinity vs. Hardness — What's the Difference?

The alkali concentration or alkaline quality of an alkali-containing substance.

Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics.

(chemistry) The state of being, or the degree to which a thing is, alkaline.

The quality or condition of being hard.

The quality which constitutes an alkali; alkaline property.

The relative resistance of a mineral to scratching, as measured by the Mohs scale.

PH values above 7

The relative resistance of a metal or other material to denting, scratching, or bending.

The quality of being hard.

An instance of this quality; hardship.

(inorganic chemistry) The quantity of calcium carbonate dissolved in water, usually expressed in parts per million (ppm).

The resistance to scratching, cutting, indentation or abrasion of a metal or other solid material.

(physics) The penetrating ability of electromagnetic radiation, such as x-rays; generally, the shorter the wavelength, the harder and more penetrating the radiation.

The measure of resistance to damage of a facility, equipment, installation, or telecommunications infrastructure when subjected to attack.

A measure of how hard a material is

The quality or state of being hard, literally or figuratively.

The cohesion of the particles on the surface of a body, determined by its capacity to scratch another, or be itself scratched; - measured among minerals on a scale of which diamond and talc form the extremes.

The peculiar quality exhibited by water which has mineral salts dissolved in it. Such water forms an insoluble compound with soap, and is hence unfit for washing purposes.

The property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale

Devoid of passion or feeling

The quality of being difficult to do;

Excessive sternness;