lecture 5 - bonding and lewis structure Flashcards
What is a molecule?
A neutral entity consisting of two or more atoms held together by chemical bonds.
What is the difference between a molecule and a compound?
Molecules can have the same element (O₂); compounds consist of different elements (H₂O).
Name the three types of chemical bonds.
Ionic, covalent, and metallic.
How is an ionic bond formed?
By the complete transfer of electrons between atoms.
What type of bond involves shared electron pairs?
Covalent bond.
What is valency?
The combining power of an element, based on the number of bonds it can form.
What is the valency of oxygen in H₂O?
Divalent (2).
What is a Lewis structure?
A diagram representing molecules showing all valence electrons.
What is the first step in drawing a Lewis structure?
Find the total number of valence electrons.
Why are multiple bonds formed in Lewis structures?
To satisfy the octet rule when single bonds do not suffice.
What is the octet rule?
Atoms bond to achieve a full set of eight valence electrons, like noble gases.
Which elements typically do not follow the octet rule?
Transition metals and elements with d-orbitals.
Define electronegativity.
The ability of an atom to attract electrons in a bond.
What does electropositivity mean?
The tendency of an atom to donate electrons.
Give an example of a compound with ionic bonding.
Sodium chloride (NaCl).
Provide an example of a compound with covalent bonding.
Water (H₂O)
