<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
Answer:
Hydrogen
Explanation:
Hydrogen can never be central atom despite its low electronegativity
A homogeneous mixture is made up of multiple different substances. (You can see different parts)
Ex: Cereal in milk or ice in soda
A heterogeneous mixture is a mixture that is mixed well. ( you can’t see the different parts)
Ex: Rain or air
Neptune planet has the coldest surface temperature
<u>Explanation:</u>
With temperatures falling to -218°C in Neptune’s upper atmosphere, the planet is one of the coolest in our Solar System. Neptune is the most faraway planet from the sun. Astronomers have speculated that Neptune's huge internal temperature and the transfer of heat between the core and outer layers might be the cause why Neptune isn't significantly more chill than Uranus.
Pressures in this area range between 1 and 5 bars and the temperature reaches a high of 72 K. At this temperature, states are becoming for methane to condense, and clouds of ammonia and hydrogen sulfide are thought to form. At its core, Neptune reaches temperatures of up to 7273 K which is equivalent to the surface of the sun.
