The answer for this question is the smallest particle of matter.
The rate equation is given as:
k = A e^(- Ea / RT)
Dividing state 1 and state 2:
k1/k2 = e^(- Ea / RT1) / e^(- Ea / RT2)
k1/k2 = e^[- Ea / RT1 - (- Ea / RT2)]
k1/k2 = e^[- Ea / RT1 + Ea / RT2)]
Taking the ln of both sides:
ln (k1/k2) = - Ea / RT1 + Ea / RT2
ln (k1/k2) = - Ea / R (1/T1 - 1/T2)
Since k2 = 4k1, therefore k1/k2 = ¼
ln (1/4) = [- (56,000 J/mol) / (8.314 J / mol K)] (1/273
K – 1/ T2)
2.058 x 10^-4 = 1/273 – 1/T2
T2 = 289.25 K
The exothermic process is a process or reaction that involves a release of energy from the system to its surroundings in various forms usually through heat, light, electricity or sound. In the four given choices, when melting a copper, you try to immerse the metal in heaping coals of fire. The metal will absorb the thermal energy coming from the coal, thus, once you retrieve the metal back, light will be emitted from it as well as heat.
Therefore, the answer is B. MELTING OF COPPER
Atomic models were developed through indirect observation even though no one had seen an atom. There were many experiments of which I know nothing about, but in the end the scientists managed to come up with a formula and various models to describe atoms.