Light has been argued as being a wave and then a particle, and back again. which of the following is right? 1. light’s true nature is as a wave. 2. light’s true nature lies somewhere in between wave and particle models. 3. light’s true nature is as a particle. 4. light’s true nature is wave-particle duality.

Both light and matter can possess particle properties and wave properties at the same time.

This quantum behavior was proposed by the French physicist Louis De Broglie in 1924 in his doctoral thesis when proposing that all matter has an associated wave, and light did not escape from that behavior. Then this was empirically tested in various experiments where light behaved as a photon (particle) and in others as particles.

Einstein also demonstrated this fact, however, in spite of being observed this behavior several times, it could not have been done simultaneously, until in 2015 a group of scientists from the Federal Polytechnic School of Lausanne (Switzerland), succeeded to perform an experiment and capture for the first time the image of the wave-particle duality of light.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.