Answer:
CaO
Explanation:
CaO is the only compound that is a non-metal and a non-metal. The rest of the compounds are ionic, or metal and non-metal.
The quantum mechanical model is used to describe the energy and most likely location of an electron.
Answer: Option A
<u>Explanation:
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The quantum mechanical model leads to the introduction of quantum numbers representing the energy levels, sub-shells, orbitals as well as spin states of the electrons. So according to the quantum numbers we can perfectly define the position and energy of any electron in an element.
According to Pauli’s principle, any two electron cannot be having same set of quantum numbers. So, using the principle quantum number, azimuthal quantum number, magnetic and spin quantum number, we can define the energy and location of an electron in the atom.
Answer:
23.2 g of Al will be left over when the reaction is complete
Explanation:
2Al + 3S → Al₂S₃
1 mol of Al = 26.98 g
1 mol of S = 32.06 g
Mole = Mass / Molar mass
63.8 g/ 26.98 g/m = 2.36 mole of Al
72.3 g / 32.06 g/m = 2.25 mole of S
2 mole of Aluminun react with 3 mole of sulfur
2.36 mole of Al react with (2.36 .3)/2 = 3.54 m of S
As I have 2.25 mole of S, and I need 3.54 S, is my limiting reagent so the limiting in excess is the Al.
3 mole of S react with 2 mole of Al
2.25 mole of S react with (2.25 m . 2)/3 = 1.50 mole
I need 1.50 mole of Al and I have 2.36, that's why the Al is in excess.
2.36 mole of Al - 1.50 mole of Al = 0.86 mole
This is the quantity of Al without reaction.
Molar mass . mole = Mass → 26.98 g/m . 0.86 m = 23.2 g
