Although the process varies slightly from one material to another, the general process is as follows:
1) Choose an appropriate container for the solid. This may be a petri dish or a beaker in which you want to prepare the solution of the solid or any other lab equipment.
2) Place the container on a mass balance, then turn the balance on. The mass balance will automatically zero-out the mass of the container, so that any mass that you add on the container will be the mass of the solid. Alternatively, you may first measure the mass of the empty container alone.
3) Add the solid using a lab spatula. The solid should be added more slowly when the reading on the scale comes close to the desired value.
4) Remove the container from the mass balance after the desired amount of solid has been added.
Answer : Option 3) Wave/Particle duality.
Explanation : The experiment on discovery of photoelectric effect revealed about the photoelectrons of light that can behave as particle or waves.
The photoelectric effect is observed when the emission of electrons or other free carriers occurs on shining a light radiation on a material. The electrons emitted from this can be called photo electrons. These photoelectrons may behave as wave or particle in duality which holds that light and matter exhibit properties of both waves and of particles.