For the reaction;
N2(g) + O2(g) = 2NO(g)
Kp = pNO²/ pN₂pO₂; (No units)
where;
pNO is the partial pressure of NO;
pN₂ is the partial pressure of nitrogen
pO₂ is the partial pressure of Oxygen
The equilibrium constant Kp is deduced from the balanced chemical equation for a reversible reaction, NOT experimental data as is the case for rate expressions in kinetics.
Kp changes with temperature considerably changing the position of an equilibrium, and, at a constant temperature, and therefore constant K, the position of an equilibrium can change significantly depending on relative concentrations/pressures of 'reactants' and 'products'.
Explanation:
Noble gas configuration is defined as the configuration which contains completely filled orbitals.
For example, oxygen atom when gain two electrons then it forms oxygen ion (
).
Atomic number of oxygen atom is 8 and so, its number of electrons will also be 8. But when it gain two electrons then it has total 10 electrons. Hence, electronic configuration of
is as follows.

Since, there are completely filled orbitals in an
ions. Therefore, it means this ion has a noble-gas configuration.
Thus, we can conclude that any specie which shows completely filled orbitals will have noble-gas configuration.
Answer:
The correct option is the second option
Explanation:
Generally, the aim of science is to understand a particular concept in the best and the most correct way possible; hence experiments are done and repeated to ensure an explanation is actually true about a concept or need modification.
The atomic models have also been a "beneficiary" of this process. The different atomic models are usually been improved upon as scientists leaned more. For example, the Dalton's atomic theory has been modified to a more correct atomic description; some of which are shown below
(1) Dalton's theory suggested that an atom is the smallest unit of a molecule. We know now from different experiments (by J. J Thompson and Rutherford) that atoms are not the smallest molecules and are made up of smaller particles known as protons, neutrons and electrons.
(2) Dalton's theory suggested that atoms of the same elements are alike in all aspects. The knowledge of isotopy shows this is not always the case. As atoms of the same elements (isotopes) have the same atomic number but different mass number; hence cannot be said to be the same in all aspects.
(3) Dalton's theory also suggested that when atoms react, they do so in fixed, simple whole number ratio. The knowledge of organic chemistry shows atoms do not always react in simple whole number ratios
There are several modifications to different postulations by scientists that have also occurred aside from this, hence the most correct answer is that "As scientists learned more, they modified the atomic model"