<span>Out of the possible answers for this question, fluorine in the second period is correct. Of the four elements fluorine, chlorine, bromine and iodine, fluorine has the largest first ionization energy, with a Enthalpy number of 1681.0. Of all the elements, helium has the highest first ionization energy figure.</span>
Answer is: B. Hydroxide ions.
An Arrhenius base is a substance that dissociates in water to form hydroxide ions (OH⁻).
For example sodium hydroxide: NaOH(aq) → Na⁺(aq) + OH⁻(aq).
Another example, balanced chemical reaction: Ba(OH)₂(aq) → Ba²⁺(aq) + 2OH⁻(aq).
According to the Arrhenius definition barium hydroxide is base.
Acids and bases when react (neutralisation) produce salt and water.
Calcium oxide + water = calcium hydroxide.
Magnesium + hydrochloric acid = magnesium chloride + hydrogen.
Sodium hydrogen carbonate + citric acid = Na3C6H5O7(aq)+3H2O(l)+3CO2(g)
Iron + salt water = 4Fe(OH)3 (rust)
Law of Definite Proportions
There is an increase in many things, you have to be specific. there is an increase in protons, the ionization energy is increased, the atomic weight, the atomic number