WEEK 2 NOTE.
FAMILIES OF ELEMENTS Elements in the same group may be said to belong to a family since they show similar properties because their atoms have the same number of valence electrons. At the same time, certain properties of the element in the same group show a gradual change with increase in atomic number. Such gradual change of property within a group is known as GROUP TREND. GROUP I The group I elements include: Lithium (Li), Sodium(Na), Potassium(K), Rubidium(Rb), Caesium (Cs), and Francium (Fr). They are univalent elements. They properties are as follows: They are good reducing agent since they can readily donate one electron to form cation. They are metals, thus they are good conductors of electricity and heat. They react vigorously with cold water to liberate hydrogen gas and form alkali, hence, they are known as ALKALI METALS. Example2Na(s) + 2H2O(l)→ 2NaOH(aq) + H2(g) The oxides of group I elements dissolve in water to give a very strong alkalis. Example K2O(s) + H2O(l)→ 2KOH(...