<span>Acetylene (C2H2) has a triple bond between the two carbons. So 3 pairs of electrons. Biomed is talking about ethylene (C2H4).</span>
Answer:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom.
Explanation:
Answer:
3.56x10^24 molecules
Explanation:
The following data were obtained from the question:
Mass of Na2SO4 = 840g
Molar Mass of Na2SO4 = (23 x2) + 32 + (16x4) =46 + 12 + 64 = 142g/mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This also gives that 1mole of Na2SO4 contains 6.02x10^23 molecules.
If 1 mole (i.e 142g) contains 6.02x10^23 molecules,
Therefore, 840g of Na2SO4 will contain = (840 x 6.02x10^23)/142 = 3.56x10^24 molecules
Always sudtract to find the answer of a irregular
