Explanation

The atomic mass of sodium is 23 g/mol.  

- This means 1 mole (6.022 × 10²³ atoms) of sodium weighs 23 grams.  

- So, the mass of one atom of sodium is:

= 23 g / Nₐ  

= 23 / (6.022 × 10²³) grams

So the correct option is: 23 / Nₐ g.

Explanation

A disaccharide is a sugar molecule composed of two monosaccharides joined together.

Fructose is a monosaccharide (a single sugar unit), not a disaccharide.

Therefore, it is the exception among the given options. 

Explanation

 If the temperature of the source of heat increases, the efficiency of a Carnot engine will increase.

The efficiency of a Carnot engine is directly related to the temperature difference between the hot and cold reservoirs.

A higher source temperature leads to a greater temperature difference and thus, a higher efficiency. 

Explanation

Sound waves diffract (bend) around corners, allowing us to hear them,

While light waves do not diffract as much, making it impossible to see around corners.

Diffraction is the bending of waves around obstacles or through openings.

Sound waves have longer wavelengths than light waves, which makes diffraction more noticeable for sound.

Polarization is a property of transverse waves, and while light waves can be polarized, sound waves cannot.

Dispersion is the separation of waves into different frequencies,

And while it can occur with light, it's not why we can hear around corners. 

Explanation

The negative gradient of electric potential is called Electric field intensity. 

Gradient:

In general, a gradient represents the rate of change of a function for a given variable.

In the context of electric fields, the gradient of electric potential indicates how quickly the potential changes as you move in a particular direction. 

Negative gradient:

The "negative" part signifies that the electric field points in the direction of decreasing potential. 

Explanation

Light intensity refers to the amount of light energy reaching a plant's surface per unit time.

This directly impacts the rate of photosynthesis as more light energy available means more ATP and NADPH can be produced, driving the Calvin cycle

Higher light intensity generally leads to increased photosynthetic activity. 

Explanation

To obtain greater dispersion by a diffraction grating, the slit separation should be decreased. 

Dispersion:

• In diffraction gratings, dispersion is the separation of light wavelengths during diffraction, with greater dispersion resulting in wider color separation.

Slit separation:

• The distance between individual slits on the grating is called the slit separation.

Relationship between slit separation and dispersion:

• Smaller slit separations lead to larger angles of diffraction for a given wavelength, resulting in greater dispersion.
• Imagine the light waves as being "bent" more by the closer slits, causing them to spread out further

Explanation

An equilibrium constant expression can be applied to an aqueous solution of table salt. 

Explanation:

An equilibrium constant expression is used for reversible reactions where the concentrations of reactants and products reach a constant state.

Table salt (sodium chloride) dissociates into Na+ and Cl- ions in water, and this dissociation can be considered a reversible reaction. Thus, the equilibrium constant can be applied to this system. 

Explanation

The principle of conservation of linear momentum is a direct consequence of Newton's Third Law of Motion.

While Newton's Second Law relates force to the rate of change of momentum (F = dp/dt),

It's the reciprocal action-reaction nature described in the Third Law that leads to the preservation of total momentum in an isolated system. 

Explanation

 The phrase "at time" means "precisely" or "exactly" when used with the verb "arrive."

So, "the train always arrives at time" means the train always arrives on schedule, without any delays.