Answer:
Refinement
Explanation:
The 3R's policy was fundamentally introduced to safeguard the animals from harsh experiments which could change their mental and physical abilities and lead to their extinction one day.
The principles of 3R's (Replacement , Reduction and Refinement) were developed long time ago. It is an strategy to perform more Humane animal research.
These are defined as,
Replacement is a method to avoid or replace the uses of animals.
Reduction is a method to minimize the number of animals used every experiment.
Refinement is a method of minimizing animal suffering and improving welfare.
Answer:
The percent recovery from re crystallization for both compounds A and B is 69.745 and 81.44 % respectively.
Explanation:
Mass of compound A in a mixture = 119 mg
Mass of compound A after re-crystallization = 83 mg
Percent recovery from re-crystallization :

Percent recovery of compound A:

Mass of compound B in a mixture = 97 mg
Mass of compound B after re-crystallization = 79 mg
Percent recovery of compound B:

Its phosphorus (P)In writing the electron configuration for Phosphorus the first two electrons will go in the 1s orbital. Since 1s can only hold two electrons the next 2 electrons for Phosphorous go in the 2s orbital. The next six electrons will go in the 2p orbital. The p orbital can hold up to six electrons. We'll put six in the 2p orbital and then put the next two electrons in the 3s. Since the 3s if now full we'll move to the 3p where we'll place the remaining three electrons. Therefore the Phosphorus electron configuration will be 1s22s22p63s23p3.
Double replacement is happening