Answer:
the first one is balanced.
Step 1:
Write molecular Formula,
Na₅P₃O₁₀
Step 2:
Assign Oxidation number to Na (which is +1) and O (which is -2), and X (unknown) for P.
(+1)₅ + (X)₃ + (-2)₁₀ = 0
Zero means overall charge on molecule is zero (Neutral).
Step 3:
Now solve for X,
(+5) + (X ÷ 3) + (-20) = 0
X ÷ 3 = -5 + 20
X ÷ 3 = +15
X = +15 ÷ 3
X = +5
Result:
Oxidation number of P is +5.
Answer: B. endergonic, not spontaneous
Explanation:
Endergonic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and
for the reaction comes out to be positive.
The Gibbs equation is:

= Gibb's free energy change
= enthalpy change
T = temperature
= entropy change
A reaction is non spontaneous when
= Gibb's free energy change is positive



Thus the reaction has to be endergonic.
Answer:
Solids
Explanation:
At standard room temperature and pressure, most of the elements are solids.
Just a few of the elements are liquids and gases at this temperature.
The periodic table is made up of metals, metalloids and non-metals. Most of these substances are actually solid.
Some non-metals are gaseous at standard room temperature.