lesson 3.04 valence electrons and bonding. vocabulary terms valence electron- an electron of an...
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Lesson 3.04
Valence Electrons and Bonding
Vocabulary Terms
• Valence Electron- an electron of an atom, located in the outermost shell.
• Bond – something that holds together. • Octet Rule/Rule of Eight - chemical rule of thumb
that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells.
• Ionic Bonding - A chemical bond that results from electrostatic attraction between positive and negative ions. It is due to transfer of electrons between a metal and a nonmetal.
Vocabulary Terms
• Covalent Bonding - A chemical bond in which electrons are shared between two atoms. The sharing of electrons between two nonmetals.
• Electronegativity - tendency for an atom to attract a pair of electrons that it shares with another atom.
• Polar Covalent Bond- a covalent bond where atoms have unequal attraction for the shared electrons.
• Non-polar Covalent Bonds – a covalent bond in which the atoms have an equal attraction to the shared electrons.
Valence Electrons
• Electrons in the outermost shell or highest energy level are called valence electrons.
Ex: Carbon – 1s2 2s2 2p2Highest energy level is second level with four
electrons(2s2, 2p2), therefore the number of valence electron for carbon is equal to 4.
Valence Electrons
Valence Electrons
Valence electrons = number of dots(Lewis Dot structure)
Ionic Bonding
Transfer of electron/s between a metal(+ion) and a nonmetal(-ion)
Ionic Bonding
• Ex: NaCl
Ionic Bonding – Let’s Practice
1) Mg + Cl
2) Al + O
Covalent Bonding
Sharing of electrons between 2 nonmetals(- ion)
Covalent Bonding
Sharing of electrons between 4 atoms of Hydrogen and 1 atom of carbon to form CH4.
Ex: CH4
Covalent Bonding- Let’s Practice
1) H + Cl
2) F + F
Polar Covalent Bond
• HF
F has a higher electronegativity than H, the atom withgreater electronegativity is able to take the electrons from the other atom making it a negative ion and the other atom as a positive ion. A Polar Covalent bond has an unevendistribution of the charge, slightly negative on one end and slightly positive on the other end.
Non Polar Covalent Bond
• H2
2 atoms of Hydrogen having the same electronegativity.Both atoms have the same strength of attraction for the electrons and are equally shared. A Non polar covalentBond have an equal attraction for the shared electrons.
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