Chemistry Questions

Here are the differences between Diamond and Graphite :

From the above analysis, Diamond is harder than Graphite because of the difference of crystalline structures.

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.

There are many isotopes of uranium and all of them have same atomic number i.e, sum of nmber of neutrons and protons.

The Law of Definite Proportion states that the same compound, wherever found or however made, always contains the same elements combined together in the same fixede ratio by weight.

Acid Precipitation or Acid rain is caused by a mix of Sulfur Dioxide, Carbon Dioxide, Nitrogen Oxides.

A Chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as Acid Rains.

A half reaction is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction.