Explanation:
The chemical formula magnesium sulfide written as MgS and NOT 
because charge on magnesium ion is +2 and charge on sulfide ion is -2.
Therefore, these charges will cancel out each other as we write the formula in simplest crisscross method.
Also, the numbers in a chemical formula display the total number of atoms attached with each other or central atom.
For example, in 
there are two chlorine atoms attached to one calcium atom.
Therefore, 
denotes one sulfur atom is attached to magnesium atom. Hence, we do not write the formula of magnesium sulfide as because this shows two magnesium atoms are attached to two sulfur atoms which is not true.
I think you forgot to give the options along with the question. I am answering the question based on my knowledge and research.All scientific theories <span>must be based on careful and rational examinations of the facts. I hope that this is the answer that you were looking for and it has actually come to your help.</span>
His measurements are precise since his pH values are close to each other in a way that it was repeated in all measurements. On the contrary to accuracy, it is the closeness to the actual pH value he should have achieved. Therefore, Jose's results are precise but not accurate since his value is not close to the actual value of pH 4.
<span>c = speed of light = 3.00 x 10^5 km/s = 3.00 x 10^8 m/s
λ = wavelength of the microwave radiation = 3.50 cm = 0.035 m
f = frequency (in Hertz) = to be determined
f = c/λ = 3.00 x 10^8 m/s / 0.035 m
f = 8.57 x 10^9 Hz Frequency</span>
