I believe the correct response would be A. More neutrons than protons.
"The reaction is exothermic and ΔH is negative" can be understood about the reaction and the enthalpy change (ΔH) during the reaction.
<u>Option: D</u>
<u>Explanation:</u>
When the reaction is positive, the process becomes endothermic, i.e. heat appears to be consumed by the system because the reaction products are more enthalpic than the reactants. When the reaction is negative, on the other hand, the process is exothermic, which is the total decrease in enthalpy is caused by heat production. Here the initial temperature is 21.0 C but increase in final temperature to 38.8 C, because if some processes require heat, others must give off heat when they take place.
Answer:
The correct answer is 5.447 × 10⁻⁵ vacancies per atom.
Explanation:
Based on the given question, the at 750 degree C the number of vacancies or Nv is 2.8 × 10²⁴ m⁻³. The density of the metal is 5.60 g/cm³ or 5.60 × 10⁶ g/m³. The atomic weight of the metal given is 65.6 gram per mole. In order to determine the fraction of vacancies, the formula to be used is,
Fv = Nv/N------ (i)
Here Nv is the number of vacancies and N is the number of atomic sites per unit volume. To find N, the formula to be used is,
N = NA×P/A, here NA is the Avogadro's number, which is equivalent to 6.022 × 10²³ atoms per mol, P is the density and A is the atomic weight. Now putting the values we get,
N = 6.022 × 10²³ atoms/mol × 5.60 × 10⁶ g/m³ / 65.6 g/mol
N = 5.14073 × 10²⁸ atoms/m³
Now putting the values of Nv and N in the equation (i) we get,
Fv = 2.8 × 10²⁴ m⁻³ / 5.14073 × 10²⁸ atoms/m^3
Fv = 5.44669 × 10⁻⁵ vacancies per atom or 5.447 × 10⁻⁵ vacancies/atom.
If it’s a negative number and a positive it might be 1.4
Liquid petrol does not ignite spontaneously when exposed to the air because there is not enough molecules that contains energy to reach the activation energy. As a result, the reaction cannot proceed and a supply of energy should be added for the reaction to occur.
