f) ionic compounds

Question 1

1.28- describe the formation of ions by the gain or loss of electrons

Answer 1

Ions are charged particles. Atoms become charged by losing or gaining electrons. Atoms that lose electron become positively charged and atoms that gain electrons become negatively charged.

Question 2

1.29- understand oxidation as the loss of electrons and reduction as the gain of electrons

Answer 2

OILRIG

Oxidation means lose of electrons. If an atom loses electron, it is oxidized. Reduction means gain of electrons. If an atom gain electron, it is reduced.

Question 3

1.30-recall the charges of common ions in this specification

Answer 3

Positive ion eg: Zn2+, Ag+, H+, NH4+

Negative ion eg: NO3+, OH-, HCO3-

Question 4

1.31- deduce the charge of an ion from the electronic configuration of the atom from which the ion is formed

Answer 4

1. Find the number of electrons in the outer electron shell.
2. Find out if it is easy for the atom to gain electron or to donate electron. (in most cases atoms that have below four electrons, donate electrons and atoms that have above 4 electrons, receive electrons)
3. Atoms that gain electron becomes negative ion and atoms that donate electron forms positive ion.

Question 5

1.32- explain, using dot and cross diagrams, the formation of ionic compounds by electron transfer, limited to combinations of elements from Groups 1, 2, 3 and 5, 6, 7

Answer 5

http://shawonnotes.ucoz.com/IGCSE_Chemistry/images/clip_image038.jpg

Question 6

1.33- understand ionic bonding as a strong electrostatic attraction between oppositely charged ions

Answer 6

When a metal metals donates electron, a non-metal non-metals receives it. The metal becomes positively charged and non-metal becomes negatively charged. As positive and negative charge attract each other, they form a electrostatic force between them

Question 7

1.34- understand that ionic compounds have high melting and boiling points because of strong electrostatic forces between oppositely charged ions

Answer 7

Melting and boiling point depends on the force that holds the particles. In case of ionic compounds, electrostatic force is very strong. So many strong forces are needed to break at once. That’s and why they have high melting and boiling point.