Answer:
6.25%
Explanation:
Given data:
Half life of lutetium-117 = 6.75 days
Percentage remaining after 27 days = ?
Solution;
Number of half lives = Time elapsed / half life
Number of half lives = 27 days / 6.75 days
Number of half lives = 4
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At 3rd half life = 25%/2 = 12.5%
At 4th half life = 12.5%/2 = 6.25%
Answer:
The concept of lewis acids and bases can explain the acidic nature of CO2. A lewis acid is a compound which can accept an electron pair whereas a lewis base is a compound which can donate an electron pair. CO2 acts as a lewis acid.
The dermal tissue is basically the outer part of the cell that protects the plant cell so in that case it would be the carbohydrate or cell wall. If you would put the choices it could have been a bit better :)
