Answer:
The changes which can be reversed are called reversible changes. These are also called physical changes. Example- Melting of ice, Tearing of paper etc are physical or reversible changes.
Explanation:
Answer:
Because the vaccine is an antigen from living, weakened or killed microorganisms that activate the immune system and the body produces protective antibodies.
Answer:
Ca has 20 protons, so neutral it would have 20 electrons, but according to the charge, 2 electrons have been lost.
Explanation:
Answer:
The crust is thinner and less dense than the mantle.
