Answer:
Mg- 27 means isotope with 12 protons and 15 neutrons.
Also 27 is mass number which express sum of protons and neutrons.
In nucleus one neutrn decays to electron and proton. Mass number remain same but Al-27 nucleus contain 13 protons and 14 neutrons. Electron is ejected out from nucleus.
Answer : When a person applies force and covers distance then the person is doing work on an object.
Explanation:
Given that,
Rate of cooling of air
Initial temperature= 80°C
Final temperature = 5°C
We need to calculate
Using newton's law of cooling


Where, 
Here,
= 25°C (surrounding temperature)
dt = 1 minute

Put the value into the formula



Hence, This is the required answer.
A. The English system uses one unit for each category of measurement.