A) They are on the outside of an atom
Answer: Physical change: It is reversible process and we can get back to orginal material. Best example is the interconversion of ice into water which inturn into vapour.
Chemical changes are irreversible and we can't get back the original material. Example combustion of coal, rusting of iron
Explanation:
1. Electrolysis of molten MgCl2 is chemical change since we can't get back MgCl2 after Electrolysis and new materials are formed.
2. It is an example rusting of iron comes under chemical changes.
The mass of the products will be equal to the mass of the reactants
3)6 electrons and neon
<h3>Further explanation </h3>
In an atom there are levels of energy in the shell and sub shell
This energy level is expressed in the form of electron configurations.
The electron configuration Oxygen (atomic number = 8) :
<em>1s²2s²2p⁴</em>
Oxygen will try to achieve stability (according to the octet rule) by binding 2 electrons so that the 2p orbits are filled with 6 electrons, so that the configuration is stable like the noble gases Neon
<em>₁₀Ne = 1s² 2s² 2p⁶</em>
Answer:
the argon because 40/4 = 10