Metal ore has other elements in it as well. Also sediment and stone might cover the ore. We don't want to have a phone with sediment on it do we? thus these few reasons are why.
They must have both cations and anions.
I hope this helps.
<span>Hydroelectric energy uses the movement of water to spin a turbine and produce electricity. Coal is a fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways. Coal use is more common than the use of hydroelectric energy.</span>
Answer:
The simplified expression for the fraction is 
Explanation:
From the given information:
O3* → O3 (1) fluorescence
O + O2 (2) decomposition
O3* + M → O3 + M (3) deactivation
The rate of fluorescence = rate of constant (k₁) × Concentration of reactant (cO)
The rate of decomposition is = k₂ × cO
The rate of deactivation = k₃ × cO × cM
where cM is the concentration of the inert molecule
The fraction (X) of ozone molecules undergoing deactivation in terms of the rate constants can be expressed by using the formula:



since cM is the concentration of the inert molecule