SC5/6 - Ionic Bonding / Covalent Bonding Flashcards
What are bonds?
They hold atoms together by forces of attraction
What is an :
-Ion?
-Anion?
-Cation?
Ion - Charged particles are formed by an atom’s loss or gain of electrons.
Anion - Negative Ion
Cation - Positive Ion0
What holds 2 oppositely charged atoms together
Ionic Bond (normally between a metal and a non-metal)
How are the ions formed linked to their group number?
The group correlates to how many electrons the atoms will lose or gain.
What is an ionic lattice?
Regular arrangement of ionic compounds held together by electrostatic forces of attraction.
How do you find the ionic formula?
You balance the negative and positive charges in an ionic compound
Examples:
work out the ionic formula of magnesium oxide
work out the ionic formula of sodium sulfide
Mg²⁺ and O²⁻
MgO
Na⁺ and S²⁻
Na2S
What is a polyatomic ion?
An ion with more than one atom
What is the formula of calcium nitrate?
Ca²⁺ and NO⁻3
This gives
Ca(NO3)2
What are the properties of an ionic compound?
High melting/boiling points
conduct only when in an aqueous solution or when molten.
What is the cathode and the anode?
anode - positive electrode
cathode - negative electrode
What is a covalent bond?
A bond between non-metals sharing a pair of electrons.
What is valency?
The number of covalent bonds formed by atoms of different elements.
How do you work out the formula of a covalent bond?
Use the group numbers to find the total amount of bonds (how many free electron spaces), then put into the formula :
eg. Carbon Sulfide
C has a valency of 4
S has a valency of 2
so then the formula is:
S = C = S
