Answer:
helium , krypton,xenon,radon, argon are noble gasses
4Al(s) + 3O2(g) --> 2Al2O3(s) This is the balanced.
From the equation:
4 moles of Al required 3 moles of O2 to produce 2 moles of Al2O3
3 moles of O2 reacted with 4 moles of Al to produce 2 moles of Al2O3
1 mole of O2 reacted with 4/3 moles of Al to produce 2/3 moles of Al2O3 (Divide by 3)
4.5 moles of O2 reacted with (4/3 *4.5) moles of Al to produce (2/3*4.5) moles of Al2O3
4.5 moles of O2 reacted with 6moles of Al to produce 3moles of Al2O3
(3) is the answer. 6 mol of Al.
The atomic number tells us the number of protons and electrons.
The atomic mass tells us the weight of the nucleus, which is the amount of protons and neutrons
Molality is one way of expressing concentration for solutions. It has units of moles of solute per kg of solvent. From the given values, we easily calculate for the moles of solute by multiplying the mass of solvent to the molality. We do as follows:
moles solute = 0.3 (10) = 3 mol solute