They start with the numbers u need to know in order to slove the problem and there has to be a story behind it
Answer:
Au
Explanation:
For the density of a face-centered cubic:
where
= molar mass of the compound
avogadro's constant
the volume of a unit cell
Given that:
Density 
= 19.30 g/cm³
a = 0.408 nm
a = 
a = 
∴
Thus, the molar mass of 197.37 g/mol element is Gold (Au).
Answer:
It would be compound.
Explanation:
It is this way because if it adds another proton it becomes more positive that nuetral, and if you add an electron it just makes the atom more dense. That is why the answer is compound. Hope this helped :)
Answer:
The answer is:
B
Explanation:
The compound in Option B is Methane.
Methane is known to be a compound which has two elements, carbon and hydrogen. It has a central atom which is surrounded by four hydrogen atoms. It's chemical formula is CH4.
Methane's outer atoms are dipoles and are in the same direction. This makes the overall molecule non-polar. The compound itself has non-polar bonds and it is non-polar itself.
NaOH is a strong base and complete dissociation into Na⁺ and OH⁻ ions.
Therefore [NaOH] = [OH⁻]
To calculate the [OH⁻], we can first find the pOH as NaOH is a basic solution.
pH + pOH = 14
Since pH = 11.50
pOH = 14 - 11.50
pOH = 2.50
We can calculate [OH⁻] by knowing pOH
pOH = -log[OH⁻]
[OH⁻] = antilog(-pOH)
[OH⁻] = 3.2 x 10⁻³ M
therefore [NaOH] = 3.2 x 10⁻³ M
