I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
An airplane is flying at a constant speed in a positive direction. It slows down when it approaches the airport where it's going to land. this is an example of negative acceleration (D).
Resistance is the name of the ratio of the voltage applied to a circuit and the current in a circuit. Goes under <span>Ohm's Law</span>
Answer:

Explanation:
given,
angular speed, ω = 3.90 x 10¹² rad/s
bond length, L = 1.10 Å
molar mass = 28.0 g/mole
Rotational Kinetic energy

now,
moment of inertia ,
......(1)
mass of O₂ = m
mass of O = M = m/2
now, mass

form equation(1)


I = 9.66 x 10⁻⁴⁷ kg.m²
putting value in Rotational kinetic energy equation


Hence, rotational kinetic energy of the molecule is equal to 