Answer: Atoms that make up reactants rearrange into new products
Explanation:
A chemical reaction is the process of breaking down the chemical bonds of the reacting substances which are commonly called as reactants and making new bonds to form new substances commonly called as products.
The products will contain the same atoms as there are in the reactants but the bonds will rearrange to form different substances.
Every chemical reaction is accompanied with absorption or release of energy.
Answer: amu
Explanation: it stands for atomic mass unit and it is the measurement that’s used to measure the mass of atoms
Here we have to get the 
of the reaction at 520 K temperature.
The of the reaction is 1.705 atm
We know the relation between and 
is 
, where = The equilibrium constant of the reaction in terms of partial pressure, = The equilibrium constant of the reaction in terms of concentration and N = number of moles of gaseous products - Number of moles of gaseous reactants.
Now in this reaction, PCl₃ + Cl₂ ⇄ PCl₅
Thus number of moles of gaseous product is 1, and number of moles of gaseous reactants are 2. Thus N = |1 - 2| = 1 mole
The given value of is 4.0×10⁻²
The molar gas constant, R = 0.082 L. Atm. mol⁻¹. K⁻¹ and temperature, T = 520 K.
On plugging the values in the equation we get,
Or, = 1.705 atm
Thus, the of the reaction is 1.705 atm
B is the.answer for this problem
