Answer:
V = a * t = 9.8 m/s^2 * 2.3 s = 22.5 m/s velocity after 2.3 s
S = 1/2 g t^2 since initial speed is zero
S = 1/2 * 9.8 m/s^2 * 5.29 s^2 = 25.9 m
It means that velocity not only has a size, but it also has a direction.
Some other vector quantities are force and acceleration.
They have sizes and directions.
Temperature, cost, and weight are quantities with only size and no direction.
Those are called "scalar" quantities.
An intersystem crossing (ISC) is a non-radiative process that involves the transition between two electronic states with different spin multiplicity. That is, when an electron is excited in a molecule in a basal singlet state (either by absorption or radiation) into a state of greater energy, an excited singlet or triplet state can be obtained.
Therefore, ISC is understood as an a non radio active transition between states with different spin multiplicity.
Correct answer is C: a radiative transition between states with the same spin.