Recall questions Flashcards
what is an ionic bond?
Electrostatic attraction between oppositely charged ions.
Describe how metals form ions and the charge they become
lose electrons, become + charged
Describe how non-metals become ions and the charge they become.
gain electrons, - charge
Explain why ionic compounds have high melting points
They have high melting points in order to weaken the attractions between the bonds and they need a lot of energy to break the bonds which are strong.
Explain why ionic compounds only conduct electricity when molten or in solution.
The ions can move (there is a flow of ions) and they can carry a charge. In a solid the bonds are too strong and compact to have a flow of ions.
What is a covalent bond?
A covalent bond is a bond between a non-metal and another non-metal. They are shared pairs of electrons.
Explain why simple covalent substances have low melting points.
They have small molecules, weak attractions between molecules,
(DO NOT MENTION COVALENT BONDS BREAKING)
Explain why simple covalent substances do not conduct electricity.
No ions or no electrons can move (delocalised)
What indicates the number of electrons lost/gained?
Group number
What is an ion?
When an atom loses or gains electrons an ion is formed.
Charge of:
Group 1
1+
Charge of:
Group 2
2+
Charge of:
Group 3
3+
Charge of:
Group 5
3-
Charge of:
Group 6
2-
