All of the elements in the periodic table are monoatomic except the 7 elements that are diatomic atoms. These 7 elements are hydrogen, nitrogen, oxygen, chlorine, bromine, iodine and fluorine. Monoatomic substances are those elements that are stable by themselves.
Explanation:
Mole = 0.5 = n/NA
n = no. of molecule
NA = avogadro number = 6.023x 10^23
so
N/NA = 0.5
N = 0.5 x 6.023 x 10^23
N = 3.0115 x 10^23
Answer: There are 
molecules in 6.73 moles of phosphorus trichloride
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
1 mole of 
contains = molecules
Thus 6.73 moles of contains = 
molecules
Thus there are molecules in 6.73 moles of phosphorus trichloride
Answer:
A conductor is a material that permits electrons to effortlessly go through it. Copper is a good conductor. Note that the valence shell has just a single electron.
While;
Materials that don't conduct are named insulators.(i.e. glass, porcelain, plastic, elastic. The covering on electrical wire is an insulator.)
Insulators don't conduct since they have a full or almost full valence shell and along these lines their electrons are firmly bound.
Explanation:
According to Bohr Rutherford model of Atom, An Atom contains three essential particles; Protons and neutrons that make up the nucleus and the electrons that circle or orbit the nucleus. The electrons circle the nucleus.
Answer:
412.1kJ
Explanation:
For the reaction , from the question -
4Fe (s) + 3O₂ (g) → 2Fe₂O₃ (s)
Δ Hrxn = Δ H°f (products) - Δ H°f (reactants)
In case the compound is in its standard state , enthalphy of formation is zero
Hence ,
for the above reaction ,
ΔHrxn =( 2 * Δ H° (Fe₂O₃ )) - [ ( 4 *Δ H° Fe ) + (3 * Δ H° O₂ )]
The value for Δ H°(Fe₂O₃ ) = - 824.2kJ/mol
Δ H° Fe = 0
Δ H° O₂ = 0
Putting in the above equation ,
ΔH rxn = ( 2 * Δ H° (Fe₂O₃ )) - 0
ΔHrxn = 2× - 824.2 kJ / mol = - 1648.4 kJ/mol
- 1648.4 kJ/mol , this much heat is released by the buring of 4 mol of Fe.
Hence ,
for 1 mol of Fe ,
- 1648.4 kJ/mol / 4 = 412.1kJ
