In order to determine the mass of a substance given the volume, we require the density. The density of iron is 7.87 grams/cm³
Now,
Density = mass / volume
Mass = density * volume
Mass = 7.87 * 4.6
36.2 grams of iron are present in the cube
Low pH = high acidity.
HF has a very low pH, so when added to a solution, it will lower the pH of the solution and therefore make it more acidic. So the answer should be B.
In mordern periodic table there are all element given in modern periodic table