(a) State three physical properties of hydrogen.

(b) Given the elements fluorine, iodine, chlorine, and bromine:
(i) Name the group to which they belong in the periodic table.
(ii) Which of them is the least reactive?
(iii) Which of them is solid at room temperature?

(c)
(i) Name two cations that can cause hardness of water.
(ii) Give two methods of removal of permanent hardness of water.

(d)
(i) State the acid-base titration that uses the following indicators:
(1) Methyl orange
(2) Phenolphthalein
(ii) Give one example each of the following salts:
(1) Hydrated
(2) Acidic
(3) Basic

(e)
(i) Arrange the following isomers in decreasing order of boiling points:
2-methylbutane, pentane, and 2,2-dimethylpropane
(ii) Write the IUPAC name of the following compounds:
(1) [tex]\(\text{CH}_3-\text{CH}_2-\text{CH}-\text{CH}_2-\text{Br}\)[/tex]
[tex]\(\text{CH}_3\)[/tex]
[tex]\(\text{CH}_3\)[/tex]
(2) [tex]\(\text{CH}_3-\text{CH}_2-\text{CH}-\text{CH}_3\)[/tex]
[tex]\(\text{CH}_2\text{OH}\)[/tex]