The earliest and simplest definition of acids and bases was suggested by . He/They defined an acid as a substance with in its formula that dissociates in water to yield and a base as a substance with in its formula that dissociates in water to yield .

Arrhenius

H, H₃O⁺

OH, OH⁻

Explanation:

The earliest and simplest definition of acids and bases was suggested by Arrhenius. He/They defined an acid as a substance with hydrogen in its formula that dissociates in water to yield H₃O⁺ and a base as a substance with OH in its formula that dissociates in water to yield OH⁻.

Acid:

An acid is the substance that sour in taste and turns the color of litmus paper from blue to red.

pH of acid is less than seven.

Base:

An acid is the substance that bitter in taste and turns the color of litmus paper from red to blue.

The pH of base is 7-14.

Arrhenius gives the simplest definition of acid and base.

Arrhenius acid:

A substance that increase the concentration of hydronium ion in solution is called acid.

HNO₃       →       H⁺ + NO₃⁻

             (H₂O)

Arrhenius base:

A substance that increase the concentration of  OH⁻ ion in solution is called base.

KOH   →  K⁺ + OH⁻

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.