Can someone help me i'm really not so good at a science

1. Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit. It is defined as the bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture.

2. REFRACTION. Refraction is another way that waves interact with matter. Refraction occurs when waves bend as they enter a new medium at an angle.

3. frequency increases, wavelength decreases. The opposite is also true—as frequency decreases, wavelength increases. ... If you make one wave crest every second, the frequency is one wave per second (1/s). Now suppose you want to increase the frequency to more than one wave per second.

4. There are two types of interference: constructive and destructive. Constructive interference occurs when the wave amplitudes reinforce each other, building a wave of even greater amplitude. Destructive interference occurs when the wave amplitudes oppose each other, resulting in waves of reduced amplitude.