Answer:
1.6 g/cm3
Explanation:
The formula for Density is actually D=m/v
m= 12.9g
v= 8 cm3

The unit is grams per centimeters cubed or g/cm3
(If you use the formula given in the question it would be D=0.62)
We generally represent an element by its symbol. provided with the atomic number and mass number or atomic mass
Atomic number is the number of protons present in an element. It is constant for an element.
The mass number of element is the sum of number of protons and number of neutrons
The atomic mass is the total mass of all the protons and neutrons present in the element (in its nucleus).
the number of electrons is equal to number of protons in a neutral atom of element.
The mass of electrons is not included in the total atomic mass of element as it is very low.
So here
12 = it is the number of protons = atomic number of element.
The true statements are
The combined mass of protons and neutrons is 24.305
Answer:
4725.6 g of (NH4)2SO4
Explanation:
Molar mass of a substance is the number of mass of the substance contained in one mole of the substance. It is also called the formula weight of the compound. The formula mass of (NH4)2SO4 is 132 g/mol Hence;
Now we know that;
1 mole of (NH4)2SO4 contains 132 g of (NH4)2SO4
35.8 moles of (NH4)2SO4 contains 35.8 * 132/1
= 4725.6 g of (NH4)2SO4
Solids tend to be dense and difficult to mold