When there was know life on the earth
There are various properties which are exhibited by substances like physical properties,chemical properties,magnetic properties,electric properties etc.
By simply observing the substance we can not get any idea about the property of a substance.One has to conduct various tests in order to reach at his or her conclusion. The scientific tests provides a better understanding about the nature of substance and the changes that happen under various conditions and parameter.
The charge of an atom before any electrons are transferred is zero.An atom as a whole is electrically neutral.
An atoms contains same number of electrons and protons. The charge of an electron and a proton is equal in magnitude but opposite in sign. The charge of a proton is 1.6 x 10⁻¹⁹C and the charge of an electron is -1.6 x 10⁻¹⁹C .Thus the charge of all the protons in an atoms is neutralized by the total charge of all the electrons.Thus an atom is electrically neutral.
when an atom loses electrons , it acquires a positive charge and when it gains electrons, it acquires a net charge.
Answer:
Newton's law of cooling says that the temperature of a body changes at a rate proportional to the difference between its temperature and that of the surrounding medium (the ambient temperature); dT/dt = -K(T - Tₐ) where T = the temperature of the body (°C), t = time (min), k = the proportionality constant (per minute),
Explanation:
