In 1869, just five years after John Newlands put forward his law of octaves, a Russian chemist called Dmitri Mendeleev published a periodic table. Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he did some other things that made his table much more successful.
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Answer:
NaHCO3 + HCl = NaCl + H2O + CO2
Explanation:
The total number of atoms of each element on either side of the equation must be equal.
Answer:
NaF>NH3>H2S>CO2
Explanation:
The boiling point of a substance depends on the magnitude of electronegativity difference and the type of bond between the atoms of the compound in question.
NaF is an ionic substance. Ionic substances have a high melting and boiling point due to the fact that the ionic lattice contains a large number of ions. This means that a lot of energy is usually required to overcome this ion-ion interaction therefore ionic compounds usually have high melting and boiling points.
Nitrogen is more electronegative than sulphur hence NH3 is more polar than H2S and consequently NH3 has a higher boiling point than H2S due to stronger dipole-dipole interaction.
CO2 is a nonpolar molecule hence it has the lowest boiling point. Only weak dispersion forces exist in CO2.