[note][sru] Diversity 1.3 Covalent Bonding 2024

1 D 1.3 Covalent Bonding CHIJ ST. NICHOLAS GIRLS’ SCHOOL Sec 2 Science 2024 Diversity D 1. Exploring Diversity of Matter by their Physical Properties D 1.3 Covalent Bonding (a) Describe the formation of a covalent molecule by the sharing of a pair of electrons in order to obtain electronic configuration of a noble gas. (b) Describe the formation of covalent bonds between two non -metallic elements. Eg. HCl, CO 2 and CH4, using ‘dot and cross’ diagrams to illustrate (c) Deduce the arrangement of electrons in other covalent molecules (d) Relate the physical properties (including electrical property) of covalent substances to their structure and bonding (e) State the number and types of atoms of each element from a given chemical formula of a substance ; highlight the various categories ; simple ions, polyatomic ions, prefixes such as mono-, di-, tri-

2 D 1.3 Covalent Bonding (A) Covalent Bonding between two atoms of the same non-metallic element Covalent bonds: https://www.youtube.com/watch?v=LkAykOv1foc Example 1: Covalent bonding between hydrogen atoms ______ pair of electrons shared gives rise to ________________________ Example 2: Covalent bonding between oxygen atoms There are _____ pairs of electrons shared; hence it is a __________ covalent bond. Molecular Formula: _________ (__________ molecule) Structural Formula: _________ Example 3: Covalent bonding between nitrogen atoms There are ____ pairs of electrons shared; hence it is a __________ covalent bond. Molecular Formula: _________ (diatomic molecule) Structural Formula: _________ Electrons of both hydrogen atoms will be shared. Covalent bond is formed when atoms of non -metallic elements _______ electrons so as to achieve the stable electronic configuration of a noble gas to form molecules. Definition of covalent bond: It is electrostatic forces of __________ between the 2 positively-charged _______ and the pair of negatively-charged __________ they _____________.

3 D 1.3 Covalent Bonding The above elements exist as diatomic molecules. The structural diagrams and chemical formulae of the diatomic molecules are given below. Hydrogen & Group VII elements (X2) Oxygen (O2) Nitrogen (N2) Non-metallic element Chemical symbol Molecular formula of the molecule Structural formula Hydrogen H Fluorine F Chlorine Cl Bromine Br Iodine I Oxygen O Nitrogen N Conclusions: 1. Two _________ of the _________________ may share electrons to achieve stable full valence shell electron configuration. 2. The atoms held together by sharing electrons is called a ____________. 3. The ___________ of electrons the two atoms ___________ is determined by the no of electr