A: because the light is lower than the hole, it will come in at in inclined angle. if the hole was say at the same level as the hole, it would shine straight to the other side of the box
Answer: Balanced molecular equation :

Total ionic equation:
The net ionic equation:

Explanation:
Complete ionic equation : In complete ionic equation, all the substances that are strong electrolyte are present in an aqueous state as ions.
Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
When sodium phosphate and zinc acetate then it gives zinc phosphate and sodium acetate as product.
The balanced molecular equation will be,

The total ionic equation in separated aqueous solution will be,

In this equation, and are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,

Hi friend
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Your answer
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Water = H2O
Number of molecules in one mole of water = 6.022 × 10²³ [Avogadro's constant]
Given number of molecules = 2.52 × 10²³
So,
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Number of moles =

HOPE IT HELPS