Answer:
The change in energy when a neutral atom in the gaseous state adds an electron to form a negative ion.
Explanation:
That is, it is the energy involved in the reaction
X(g) + e⁻ ⟶ X⁻(g)
For most elements, the electron affinity is negative.
However, there are two major exceptions — the values are positive for the elements of Groups 2 and 18 (note the troughs in the graph below).
The atom that is oxidized : Cr
The oxidizing agent : H₃PO₄
<h3>Further explanation</h3>
Reaction
2 H₃PO₄ (aq) + 2Cr(s) → 2 CrPO₄ (aq) + 3H₂(g)
Atoms undergoing a reduction reaction (decrease in oxidation number) and an oxidation reaction (increase in oxidation number)
H⁺(in H₃PO₄) =+1
H₂=0
Cr = 0
Cr³⁺(in CrPO₄ )
the oxidizing agent.⇒which undergoes a reduction reaction and oxidizes another compound/element : H₃PO₄
1) All matter is made of atoms. 2) Atoms are indivisible and indestructible.
The atomic number of an element is based on the number of protons in the atomic nuclei of its atoms.
