<u>Answer:</u> The mass defect for the formation of phosphorus-31 is 0.27399
<u>Explanation:</u>
Mass defect is defined as the difference in the mass of an isotope and its mass number.
The equation used to calculate mass defect follows:
![\Delta m=[(n_p\times m_p)+(n_n\times m_n)]-M](https://tex.z-dn.net/?f=%5CDelta%20m%3D%5B%28n_p%5Ctimes%20m_p%29%2B%28n_n%5Ctimes%20m_n%29%5D-M)
where,
= number of protons
= mass of one proton
= number of neutrons
= mass of one neutron
M = mass number of element
We are given:
An isotope of phosphorus which is 
Number of protons = atomic number = 15
Number of neutrons = Mass number - atomic number = 31 - 15 = 16
Mass of proton = 1.00728 amu
Mass of neutron = 1.00866 amu
Mass number of phosphorus = 30.973765 amu
Putting values in above equation, we get:
![\Delta m=[(15\times 1.00728)+(16\times 1.00866)]-30.973765\\\\\Delta m=0.27399](https://tex.z-dn.net/?f=%5CDelta%20m%3D%5B%2815%5Ctimes%201.00728%29%2B%2816%5Ctimes%201.00866%29%5D-30.973765%5C%5C%5C%5C%5CDelta%20m%3D0.27399)
Hence, the mass defect for the formation of phosphorus-31 is 0.27399
The answer to your question is A. the wind exerts a force on the leaf causing its motion to change
12. F - Most of these elements are metals.
13. C - Ability to rust
the equation of the parabola is given as 
. D
<h3>How to find the parabola</h3>
Given the focus(6,2) and the directrix, y = 0
Use the formula
= (y - 0)
Find the square of both sides, square root is removed from the side with it and square added on the other side
Expand the expression and bring all terms to one side
= 
Collect like terms
Make 'y' the subject of the formula
Divide through by 4 and substrate 4 from 40 to give a perfect quadratic equation
Divide factor by 4 to give 1
Simplify the expanded quadratic equation
, we have 
Then insert in place into previous equation
Thus, the equation of the parabola is given as
Learn more about a parabola here:
brainly.com/question/4061870
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