We are working through a practise paper from the Ministry website
You should have completed question 1 last night. Do question 2 tonight. See last night’s post for instructions on how to hand this work in.
Also revise writing chemical formulae, word equations, fully balanced chemical equations and the reactions of acids and bases by watching the embeded videos below. They are based on lessons and lesson notes I did with you earlier in the year. There is video of practical work you carried out when you were making salts by neutralising acids with bases.
What happens when sodium and chlorine atoms react?
Sodium has one electron in its outer shell. Chlorine has seven electrons in its outer shell. When they react sodium loses an electron to become a sodium ion with a charge of +1. Chlorine atoms accept an electron to become chloride ions with a charge of -1. After reacting the sodium and chloride ions have a full outer shell of electrons. A full outer shell of electrons is a stable arrangement. The inert gasses in group 18 of the periodic table all have a full outer shell and characteristically are very unreactive (they don’t easily combine with other elements). The new substance sodium chloride is made up of ions. Compounds that have ions bonded together are called ionic. The ions are held together by powerful electrostatic forces. Ionic compounds typically have high melting and boiling points as a consequence.
Homework… how much of this do you understand?
Watch the video especially the bit that deals with the changes to sodium and chlorine atoms when they react with each other. Magnesium has two electrons in its outer shell and it burns in chlorine gas like sodium. Draw sodium and chlorine atoms and show how ions are produced when they react. What are the charges of the ions? what is the formula of magnesium chloride?
