The hardest material is diamond. The hardest artificial substance would wurtzite boron nitride. That's basically just man-made diamonds.
The number of moles of 210 grams of NaHCO₃ is 2.5 moles.
<h3>How to find the Number of moles ? </h3>
To calculate the number of moles use the formula
Number of moles = 
Mass of NaHCO₃ = 210 g
Now we have to find the Molar mass of NaHCO₃
= Atomic mass of Na + Atomic mass of H + Atomic mass of C + 3 (Atomic mass of O)
= 23 + 1 + 12 + 3 (16)
= 36 + 48
= 84 g/mol
Now put the value in above formula we get
Number of moles = 
= 
= 2.5 moles
Thus from the above conclusion we can say that The number of moles of 210 grams of NaHCO₃ is 2.5 moles.
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Answer:
Sand has a strong non-polar covalent connection, that prevents water to break it down.
Explanation:
Sand being composed of quartz and small particulars of minerals can only be dissolved in hot acids, unlikd sugar which can easily be broken down by water, due to the large magnetic molecular propery of water and the ability to evolve sugar in an Intermolecular manner.
3 moles of NaOH reacts with 1 mole of phosphoric acid.
<h3>What is the moles ratio of the NaOH and Phosphoric acid reaction?</h3>
The moles ratio of the reaction between NaOH and Phosphoric acid is given by the equation of the reaction below:

Based on the equation of the reaction, 3 moles of NaOH reacts with 1 mole of phosphoric acid.
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Carbon is a chemical element of atomic number 6, a non metal which has two main forms.