We have that the the density of FeS is mathematically given as
From the question we are told
Iron(II) sulfide has a primitive <em>cubic</em> unit cell with <em>sulfide</em> ions at the <em>lattice points.</em>
The ionic radii of iron(II) ions and sulfide ions are 88 pm and 184 pm, respectively.
What is the density of FeS (in g/cm3)?
<h3>
Density</h3>
Generally the equation for the Velocity is mathematically given as

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brainly.com/question/13981855
A stupid person doesn’t have much intelligence or imagination, and they go through life making decisions that seem to lack all common sense. If you’ve got a brain but you don’t use it, you might be a bit stupid.
Answer:
a. 4KCN
Explanation:
Four is a coefficient found in the chemical formula 4KCN.
KCN is potassium cyanides.
A coefficient is a number that is written before a chemical compound. It is usually used to balanced reaction expression.
Chemically such numbers indicate the number of moles or volume of that specie.
Since KCN is the only compound with 4 before it, so, the solution is KCN
As the temperature of the system increases, the energy of the system also increases, speeding the system up.
I think is letter C, good luck!