Explanation

In an atom, no two electrons can have the same set of four quantum numbers.

This is known as the Pauli Exclusion Principle.

The four quantum numbers are: 

Explanation

The total energy of a hydrogen atom in its ground state is negative. 

The energy of a hydrogen atom in its ground state is typically represented as -13.6 eV.

A negative energy value indicates that the electron is bound to the nucleus and requires energy to be overcome to escape.

The ground state is the lowest energy level an electron can occupy in a hydrogen atom. 

Explanation

The reverse process of the photoelectric effect is the production of X-rays when electrons are decelerated.

In the photoelectric effect, light (photons) interacts with a material, causing electrons to be emitted.

Explanation

 The precise definition of organic chemistry is the Study of carbon-containing compounds. 

Organic chemistry focuses on the study of compounds that contain carbon, regardless of whether they are hydrocarbons or their derivatives.

While hydrocarbons are a subset of organic compounds, the definition encompasses all carbon-based molecules

Explanation

The wave velocity in any medium depends on all of the above:

Elasticity:

A medium's elasticity determines how easily it can resist deformation and return to its original shape when force is applied.

Higher elasticity means the wave can travel faster through the medium. 

Density:

The density of a medium also affects wave velocity.

Denser media tend to slow down wave propagation. 

Homogeneity:

A homogeneous medium has consistent properties throughout, meaning the wave velocity will be uniform in all directions. 

Explanation

Speed = 3000 RPM (revolutions per minute)

Step 1: Convert RPM to revolutions per second (RPS)

Step 2: Convert revolutions to radians

Since 1 revolution = 2π radians:

50 rev/sec×2π= 100π radians/sec

Explanation

An allergy is an immune system response to a foreign substance that's not typically harmful to your body.

Explanation

The efficiency of a Carnot engine is defined as the ratio of the heat absorbed from the hot reservoir (heat accepted) to the heat rejected to the cold reservoir (heat rejected).

This efficiency is directly related to the temperature difference between the two reservoirs. 

Explanation

Alkaline earth metals: These elements have two valence electrons in their outermost s orbital.

3rd period: In the third period, the outermost shell is the 3rd shell. 

Therefore, the electronic configuration of an alkaline earth metal in the 3rd period is [Ne] 3s².

Explanation

The Van der Waals constant "a" represents the magnitude of intermolecular attractions.

A higher "a" value means stronger intermolecular forces.

- He and H₂ are very light, nonpolar, and have weak intermolecular forces.

- N₂ is also nonpolar but heavier than He and H₂.

- CH₄ (Methane) is nonpolar but larger and more polarizable, so it has stronger London dispersion forces.

→ Therefore, CH₄ has the highest "a" value among the given options.