Answer:

Explanation:
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In this case, since there is a 2:2 mole ratio between sodium peroxide and water according to the given reaction, it is possible to apply the following stoichiometric setup for the calculation of the required mass of water:

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The number of oxygen atoms are 6 atoms
<u><em>Explanation</em></u>
According to the law of mass conservation the number of reactant atoms is equal to number of product atoms.
For given equation to obey the law of mass conservation it need to be balanced as below
4 Al + 3 O₂ → 2 Al₂O₃
Al₂O₃ is the product,therefore the number of oxygen atom
= coefficient in front of Al₂O₃ × subscript of O
=2 x 3 = 6 atoms
Answer:
Explanation:
Atoms are the thing that make up molecules and compounds. Molecules contain two or more atoms and are held together by covalent bonds
1:1
Fe has a charge of 2+ while O has a charge of 2-.
Formula: FeO
Explanation:

The maximum wavelength of light that can cause this reaction is 420 nm.
a) The wavelength given lies in the range of visible light range that is from 400 nano meters to 700 nano meters.
The light with wavelength of 420 nm is found in the range of visible light.
b)The maximum strength of a bond :

where,
E = energy of photon = Energy required to break single molecule of nitrogen dioxide
h = Planck's constant = 
c = speed of light = 
= wavelength = 


Energy required to break 1 mole of nitrogen dioxide molecules:


(1 J = 0.001 kJ )
285.13 is the maximum strength of a bond, in kJ/mol, that can be broken by absorption of a photon of 420-nm light.
c) the photodissociation reaction showing Lewis-dot structures is given in an image attached.