When we write a formula of a compound in its simplest form, it is empirical formula.
Given the molecular formula is = C₁₈H₃₆
Now we can relate both empirical and molecular formula as;
Molecular formula = n x empirical formula
C₁₈H₃₆ = 18 x CH₂
So the empirical formula of C₁₈H₃₆ is CH₂
Answer and Explanation:
<u>D) 7 is the answer</u>
Together, the crust and the upper part of the mantle form the lithosphere, Earth's solid outer shell. This rocky, brittle layer is broken up into seven major and several minor tectonic plates (also known as lithospheric plates) that fit together like puzzle pieces.
<u><em>#teamtrees #PAW (Plant And Water)</em></u>
Answer: Option D is correct.
Explanation: Equation given by de Broglie is:

where,
= wavelength of the particle
h = Planck's constant
m = mass of the particle
v = velocity of the particle
In option A, football will have some mass and is moving with a velocity of 25 m/s, hence it will have some wavelength.
In Option B, unladen swallow also have some mass and is moving with a velocity of 38 km/hr, hence it will also have some wavelength.
In Option C, a person has some mass and is running with a velocity of 7 m/hr, hence it will also have some wavelength.
As, the momentum of these particles are large, therefore the wavelength will be of small magnitude and hence, is not observable.
From the above, it is clearly visible that all the options are having some wavelength, so option D is correct.