Answer:- C. Hafnium.
Solution:- Mass of the sample is 46.0 g and it's volume is
.
From mass and volume, we can calculate it's density using the formula:
![density=\frac{mass}{volume}](https://tex.z-dn.net/?f=density%3D%5Cfrac%7Bmass%7D%7Bvolume%7D)
![density=\frac{46.9g}{3.5cm^3}](https://tex.z-dn.net/?f=density%3D%5Cfrac%7B46.9g%7D%7B3.5cm%5E3%7D)
![density=\frac{13.4g}{cm^3}](https://tex.z-dn.net/?f=density%3D%5Cfrac%7B13.4g%7D%7Bcm%5E3%7D)
On the basis of the density, this substance could either be mercury or hafnium. Since the substance is a solid at room temperature where as mercury is liquid. So, it can't be mercury.
The right choice is C) Hafnium.
Calcium chloride is the salt of hydrochloric acid and calcium hydroxide. Calcium hydroxide is usually not considered a strong base, and I believe this is because of it's low solubility. HCl is a strong acid, and so the salt should be slightly acidic.
When a strong acid and strong base are combined, it forms a neutral salt. Therefore, Na₂SO₄ is a neutral salt because it is the product of NaOH (a strong base) and H₂SO₄ (a strong acid).
The mass would be 2 hydrogen electroydtyetes