<span>your answer is Ca3</span>(PO4)2<span>, </span>
They are called isotopes.
Example of isotopes are Hydrogen and deuterium.
Hydrogen is 1 proton and 0 neutrons.
Deuterium is 1 proton and 1 neutron
The density of the block will be "7.11 gm/cm³". A further explanation is provided below.
Given values are:
Density of iron,
Mass of block of metal,
Volume of block,
By using the formula,
→ 
then,
→ The density of block will be:
= 
= 
= 
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