It is called exothermic reaction because it releases heat and light and it is called combustion reaction because it is reacting and is being oxidised by O2 to MgO.
It can also be called as oxidation reaction since Mg is oxidised to MgO.
Democritus, a Greek philosopher, first developed the idea of atoms (around 460 B.C., I believe).
Hope this helps!
Proton: positive- mass equal to neutron
Electron: negative- mass 1/1840 mass of proton
Neutron: no charge- same mass as proton
Mass = m = 40 grams
Volume = V = 9 cm³
Density = d = ?
Density is defined as the ratio of mass and volume.
So,
d = m/V
Using the values, we get
d = 40/9 = 4.44 g/cm³
This means the density of material would be 4.44 g/cm³
The equation for the reaction between the calcium nitrate and chromium sulfate to form calcium sulfate and chromium(iii) nitrate is,
3Ca(NO3)2 + Cr2(SO4)3 --> 3CaSO4 + 2Cr(NO3)3
The balanced equation shows that for every 1 mole of chromium sulfate, there will be 3 moles of calcium nitrate. Therefore for this item, there will be 4.55 moles times 3 which is equal to 13.65.
