Answer:To determine the number of valence electrons in an atom of a representative element, you can look at its position on the periodic table. Representative elements are also known as the main group elements and are located in groups 1-2 and 13-18 of the periodic table.
The number of valence electrons in an atom of a representative element is equal to the group number. For example, the elements in group 1 (also known as the alkali metals) have 1 valence electron, while the elements in group 2 (the alkaline earth metals) have 2 valence electrons. The elements in group 13 (the boron group) have 3 valence electrons, and so on, up to group 18 (the noble gases), which have a full set of 8 valence electrons (except for helium, which has only 2).
For example, let's consider the element sodium (Na), which is in group 1. Sodium has 1 valence electron because it is in group 1. Similarly, the element carbon (C), which is in group 14, has 4 valence electrons because it is in group 14.
Knowing the number of valence electrons in an atom is important because it helps to determine the chemical properties and reactivity of the element. Atoms with the same number of valence electrons tend to have similar chemical properties and can form similar types of chemical bonds.
Step-by-step explanation: