Answer:
According to the proton theory of acids and bases by J. Brønsted and T. Lowry, the acid is<u> proton donor</u>.
Explanation:
According to the Bronsted lowry concept an acid is substance that gives protons or hydrogen ion while,
Base is substance that accept hydrogen ion or proton.
Consider the following example:
NH₃ + HCl → NH₄⁺ + Cl⁻
In this example HCl is Bronsted lowry acid it gives H⁺ while ammonia is Bronsted lowry base because it accept H⁺.
This also gives the concept of conjugate acid and base. In given example Cl⁻ is conjugate base of HCl while NH₄⁺ is conjugate acid of ammonia.
Halogens is defined as the group of 7 periodic table. As, every periodic table contains 7 valence electrons and they only need 1 more to complete an outer shell, that is why they are extremely reactive. And according to the law that recurring patterns of the properties of elements arise when they are arranged in order of increasing atomic number. As the halogen all act very similarly with each other in chemical reaction, it is true.
