It is based on Relative DENSITY.............
Answer: 
Explanation:-
Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
As zinc is more reactive than copper, it could easily displace copper from its aqueous solution and thus leads to formation of zinc (II) sulfate and pure copper.
The chemical reaction can be represented as :

The phases are represented as (s) for solid sate, (l) for liquid state, (g) for gaseous state and (aq) for aqueous state.
Answer:
Hope this helps
Explanation:
All object continues to be in its state of rest or uniform motion unless acted upon by an external unbalanced force. The rate of change of momentum of an object is proportional to the unbalanced force in the direction of the force. 3rd law every action has an equal and opposite reaction.
Answer:
That means an atom with a neutral charge is one where the number of electrons is equal to the atomic number. Ions are atoms with extra electrons or missing electrons. When you are missing an electron or two, you have a positive charge. When you have an extra electron or two, you have a negative charge.