The chemical formula for chlorophyll is C55H72O5N4<span>Mg. Only 1 of the 137 atoms comes from magnesium.
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The answer for the given question above is IONIC. <span>Ionic substances form giant ionic </span>lattices<span> containing oppositely charged ions. They have high melting and boiling points, and </span>conduct<span> electricity when melted or dissolved in water.</span>
Sliding or rolling friction
MgF is an ionic compound because it's bond is between a metal and a non-metal
A + BC ---> AB + C
So here one reactant (A) is accepting a group which is being given by another compound (BC) however the A is not giving any group / element or ion
So this single displacement
Similarly in the given reaction
the anion OH- is only being replaced
The element Ca accepts OH- and H2O loses the same group to form new element H2
So the correct answer is
Single replacement also known as single displacement.