Question

Define activation energy, half-life, and zeroth order reaction in your own words.

Answer 1

Activation energy

The minimum amount of kinetic energy requirement that must be met for a chemical reaction to occur is called the activation energy, Ea

activation energy is the energy which must be available to a chemical or nuclear system with potential reactants to result in: a chemical reaction , nuclear reaction , or various other physical phenomena.

Half life

Half life is the time required for a nuclear reactant to react or decayed by emitting the nuclear emissions such as alpha, beta and gamma radiations to exactly half the amount of initial amount present. The amount can be estimated in mass , atomic numbers.

Half life is otherwise defined as the time taken to reduce the activity of a radio active substance to become half of the initial value.

Zeroth order reaction

Unlike the other orders of reaction, a zero-order reaction has a rate that is independent of the concentration of the reactants. As such, increasing or decreasing the concentration of the reacting species will not speed up or slow down the reaction rate. Zero-order reactions are typically found when a material that is required for the reaction to proceed, such as a surface or a catalyst, is saturated by the reactants.
The rate law for a zero-order reaction is rate = k , where k is the rate constant. In the case of a zero-order reaction, the rate constant k will have units of concentration/time, such as M/s .