Select all that apply to the property of hardness.

Hardness is a physical property

Friedrich Mohs developed the standard hardness scale.

Diamond can scratch quartz.

Explanation:

hope it helped! ^_^

hardness is a physical property

hardness is indicative of the strength of chemical bonds between elements.

hardness is a determined through a complicated processs that requires expensive instruments.

Friedrish Mohs developed the standard hardness scale.

Diamomd can scratch quartz

b. acid is the correct answer @jayxboof all social media

acid : acids are those which accepts an electron-pairs.

base : bases are those which donates ab electron-pairs.

alkali : it is a base that dissolves in water. it is basically a base and the ph greater than 7.

hydroxide ion : it is a poly-atomic ion which is negatively charged.

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a