Draw an electron dot diagram to show the formation of each of the following compounds:
Methane
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Solution
In electron dot representation, the valence or outermost electrons in an atom are represented by putting dots (.) on the symbol of the element, one dot for each valence electron. Example, Sodium atom (Na) has one electron in its outermost shell, so the electron dot structure of the Sodium atom can be represented as:
The bond that is formed by the sharing of electrons between two atoms is known as a covalent bond.
It is formed when both the atoms which are reacting require electrons to attain the nearest noble gas configuration.
Compounds in which atoms are connected to each other via covalent bonds are termed as covalent compounds. Example, Methane .
Methane consists of four Hydrogen (H) atoms and one Carbon (C) atom.
Hydrogen has an atomic number 1. Its electronic configuration is 1. Hence, it has only one electron in the valence shell and this is not a stable arrangement of electrons.
In order to achieve a stable arrangement, the valence shell must contain 2 electrons. Thus, H needs one more electron to become stable and attain a stable noble gas configuration of Helium (He)
Carbon has an atomic number 6. Its electronic configuration is 2,4. Hence, it has four electrons in the valence shell and needs four more electrons to attain a stable noble gas configuration of Neon (Ne).
Thus, one Carbon atom shares its four electrons with four Hydrogen atoms to form four single covalent bonds between 1 C and 4 H atoms. Hence, a molecule is formed.