The density of an object is mass / volume. These units are unusual but since you are reporting your answer in kg/L, the actual conversion is unnecessary
d = m/V
d = 7.2 kg / 9 L
d = 0.8 kg / L
Answer:
Trioxocarbonate (iv) are salts derived from trioxocarbonate (iv) acid when it reacts with metals and metallic oxides. All trioxocarbonate (iv) salts of Sodium (Na), Potassium (K) and Ammonium(NH4+) are soluble while all others are insoluble.
I guess if you mix them together, the chalk would get less harder.
Radioactive is the most penetrating nuclear radiation