Answer:
Reflection involves a change in direction of waves when they bounce off a barrier; refraction of waves involves a change in the direction of waves as they pass from one medium to another; and diffraction involves a change in direction of waves as they pass through an opening or around a barrier in their path.
Explanation:
https://www.physicsclassroom.com/class/waves/Lesson-3/Reflection,-Refraction,-and-Diffraction#:~:text=Diffraction%20of%20Waves-,Reflection%20involves%20a%20change%20in%20direction%20of%20waves%20when%20they,a%20barrier%20in%20their%20path.
Answer: 
Explanation:
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Beta decay : In this process, a neutron gets converted into a proton and an electron releasing a beta-particle. The beta particle released carries a charge of -1 units.

The given reaction would be represented as:

Answer:
The least substituted product (anti-Markovnikov)
Explanation:
The ROOR is used in the addition reaction of HBr to an organic substance (an alkene for example).
In normal conditions (with no ROOR) the adition of the halogen will be performed in the most substituted C (following the rule of Markovnikov that says that the stability increases with the more substituted is the C).
But in presence of ROOR, the reaction takes other mechanism (free radicals), and the product in this case is the one with the Br added in the least substituted C.
Claw technique is what is represented