Answer: a
Explanation: because an Arrhenius acid is a compound that increases the H + ion concentration in aqueous solution. An Arrhenius base is a compound that increases the OH − ion concentration in aqueous solution.
Answer: electron donor.
Explanation:
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions
when dissolved in water and an acid is defined as a substance which donates hydronium ions
in water.
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.

Here
acts as lewis base and
act as lewis acid.
Thus lewis base is defined as an electron pair donor.
No but i am glad i havent
Ultraviolet has more energy. You can tell because it has a shorter wave. The longer the wave is on the electromagnetic spectrum the less energy is stored.