Covalent Bonding Flashcards
(12 cards)
What does covalent bonding occur between?
non-metals only
What happens when non-metals react?
they share electron pairs to acquire a stable electron configuration and form molecules
Covalent bond definition
The strong electrostatic force of attraction between the shared pair of electrons (negative) and the positive nuclei (positive) of the atoms.
Drawing covalent dot and cross diagrams
Only outer shell electrons are shown
Displayed formula example - hyrdogen
H - H. The line represents the covalent bond. If there are two shared electron pairs, there are two lines, and three if there are three.
Covalent bonding structure
Simple molecular/covalent structure - weak intermolecular forces between the molecules; strong covalent bonds inside the molecules.
Melting and boiling points
The melting and boiling points of simple molecular structures are low because the weak intermolecular forces do not require a lot of energy to break as they are weak
Do simple molecular structures conduct electricity?
No - simple molecular structures cannot conduct because there are no ions or delocalised electrons. Molecules are neutral
What is needed to be present for a substance to conduct electricity?
ions or delocalised electrons
Are simple molecular substances soluble?
no - they don’t dissolve and are insoluble in water
What does a bigger molecule mean in terms of intermolecular forces?
The bigger the molecule, the stronger the intermolecular forces between the molecules
Explain why the boiling point of the halogens increase down the group
As you go down group 7, the molecules get bigger. Bigger molecules have stronger weak intermolecular forces between the molecules. This means more energy is needed to break down the forces so there is a higher boiling point.
