Covalent bonding Flashcards
What is a covalent bond?
A covalent bond is a shared paired of electrons.
How are covalent bonds formed?
Non-metal elements join together by sharing electrons to form covalent bonds. The sharing of electrons allows the atoms to gain stability.
What is a diatomic molecule?
A diatomic molecule contains two atoms joined together.
Do covalent substances have high or low melting and boiling points?
Covalent substances made up of molecules have low melting and boiling points.
Do covalent network substances have high or low melting and boiling points?
Covalent network substances have very high melting and boiling points.
Do covalent substances conduct electricity?
Covalent substances do not conduct electricity in any state because there are no charged particles that are free to carry the current.
What must a substance have for it to conduct electricity?
For a substance to be able to conduct electricity it must have a charged particles that are free to move to carry the current through the structure.
what atoms are diamond and graphite made from?
Diamond and graphite have covalent network structures made of carbon atoms.
In diamond how many outer electrons are in each carbon atoms are used to form covalent bonds?
In diamond, all 4 outer electrons in each carbon atom are used to form covalent bonds.
In graphite how many outer electrons are in each carbon atom are used to form covalent bonds?
In graphite only 3 of the outer electrons are used to form covalent bonds.
What does it mean when electrons are delocalised?
Electrons which are delocalised are free to move from atom to atom - they are not restricted to one particular atom.
Does diamond have delocalised electrons?
Diamond does not have delocalised outer electrons so does not conduct electricity.
Does graphite have delocalised electrons?
Graphite has delocalised outer electrons which allow it to conduct electricity.
Do covalent network substances dissolve in solvents?
Covalent network substances do not dissolve in any solvents.
Do covalent molecular substances dissolve in solvents?
Some covalent molecular substances are soluble in water, e.g. glucose. Other covalent substances may dissolve on other solvents such as ethanol or acetone. Covalent network substances do not dissolve in any substances.
