Answer:
6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.
Explanation:
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given:
Concentration is decreased to 1.56 % which means that 0.0156 of
is decomposed. So,
= 0.0156
Thus,
kt = 4.1604
The expression for the half life is:-
Half life = 15.0 hours
Where, k is rate constant
So,

<u>6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.</u>
O2 is an element As it contains just one kind of atom, O2 is an element,
Uranium provides nuclear fuel used generate electricity in nuclear power station,also used by the military to power nuclear submarines and in nuclear weapons.
Double replacement is happening
Answer:
The particles move faster and are far apart
Explanation:
A substance may exist in three states of matter; solid, liquid and gas.
In the solid state, there is very strong intermolecular forces between the particles of the substance. They can only vibrate or rotate about their mean positions but can not translate.
In the liquid state, the particles of the substance have a greater degree of freedom than in the solid. The magnitude of intermolecular forces is lower than in solids, the molecules can move at low speeds.
In a gas, the molecules are separated from each other with negligible intermolecular interaction hence they move at very high speed.
Therefore, for the water gas particles in the air above the cup; the particles move faster and are far apart.