Answer:
The correct answer would be 3. The number of atoms of each element in the reactants equals the number of atoms of each element in the products.
Explanation:
The law of conservation of matter states that energy cannot be created or destroyed, only transfered. Thus, option 3 is correct.
2n² rule:
This rule is used to determine number of electrons in particular shell.
n=1 means K shell
n=2 means L shell
n=3 means M shell
n=4means N shell
The first K shell can hold upto 2 electrons, L shell can hold up to 8, third M shell can hold up to 18and the fourth N shell can hold upto 32 electrons. This rule of arrangement of electrons according to the shell is known 2n2 rule where n means number of shell.
For example: There is one proton in the nucleus of hydrogen atom, which moves in K shell path. It has no neutron.
273 Kelvin, 0 degrees Celsius, 32 degrees Fahrenheit