1. Q: How do atoms of different elements combine to form compounds?
Q: How are ionic bonds formed?
Q: What is an ion?
Q: How is a sodium ion, Na+, form from a sodium atom?
Q: How is a chloride ion, Cl-, formed from a chlorine atom?
Q: How do atoms of Group 1 elements form ions?
Q: How do atoms of Group 2 elements form ions?
Q: How do atoms of Group 6 elements form ions?

2. A: By the transfer of electrons to form cations and anions.
A: By the formation of new chemical bonds.
A: By the loss of one (the outer) electron.
A: Atoms or groups of atoms with a positive or negative charge.
A: By the loss of the one electron in their outermost electron shell, to give a 1+ ion.
A: By the gain of one electron into its outermost shell.
A: By the addition of two electrons to their outermost electron shell, to give a 2- ion.
A: By the loss of the two electrons in their outermost electron shell, to give a 2+ ion.

3. Q: How do atoms of Group 7 form ions?
Q: What does the ending –ide mean in the name of an ionic compound?
Q: What does the ending –ate mean in the name of an ionic compound?
Q: What are the chemical formulae for: sodium chloride, sodium oxide, sodium hydroxide?
Q: What are the chemical formulae for: calcium nitrate, calcium sulfate, calcium carbonate?
Q: What are the chemical formulae for: aluminium chloride, ammonium sulfate, iron(III) oxide?
Q: What is meant by the term ‘lattice structure’?
Q: Describe and explain the melting points of sodium chloride and magnesium oxide.

4. A: The anion contains only one type of atom (except for hydroxides).
A: By the addition of one electron to their outermost electron shell, to give 1- ions.
A: NaCl, Na2O, NaOH.
A: The anion contains two or more different elements and one of them is oxygen (except for hydroxides).
A: AlCl3, (NH4)2SO4, Fe2O3.
A: Ca(NO3)2, CaSO4, CaCO3.
A: High melting and boiling points due to the very strong bonds between the ions – it takes a lot of energy to break these bonds.
A: A structure consisting of a regular arrangement of ions, held together by strong electrostatic forces (ionic bonds) between oppositely-charged ions.

5. Q: Describe and explain the electrical conductivity of ionic compounds.
Q: Describe the solubility in water of sodium, potassium and ammonium salts.
Q: Describe the solubility in water of nitrate salts.
Q: Describe the solubility in water of chloride salts.
Q: Describe the solubility in water of sulfate salts.
Q: Describe the solubility in water of carbonates and hydroxides.
Q: What is a precipitation reaction?
Q: What is a precipitate?

6. A: All common salts are soluble.
A: They conduct electricity when aqueous or molten, as in these states the ions are free to move so they can carry electric current.
A: All common salts are soluble, except silver and lead.
A: All are soluble.
A: All common salts are insoluble, except for sodium, potassium and ammonium.
A: All common salts are soluble, except lead, barium and calcium.
A: Insoluble solid in a solution during a chemical reaction.
A: A reaction that results in an insoluble product.

7. Q: What is a barium meal?
Q: Why is barium sulfate used in barium meals?
Q: Describe the results of flame tests for solids or solutions containing the following ions: Na+, K+, Ca2+, Cu2+.
Q: What is the test for carbonate ions?
Q: What is the test for sulfate ions?
Q: What is the test for chloride ions?
Q: What is spectroscopy and what is it used for?
Q: Name two elements discovered through spectroscopy.

8. A: Barium sulfate swallowed just before an X-ray.
A: It is opaque to X-rays; it is safe to use as, although barium salts are toxic, its insolubility prevents it entering the blood.
A: Barium sulfate swallowed just before an X-ray.
A: Add dilute acid. If carbonate is present, CO2 gas will be produced. You can test for this by bubbling through limewater – it turns milky in the presence of CO2.
A: Na+ = yellow/orange flame. K+ = lilac flame. Ca2+ = brick-red flame. Cu2+ = blue-green flame.
A: Add dilute HNO3, followed by silver nitrate solution. A chloride gives a white precipitate of silver chloride.
A: Add dilute HCl, followed by barium chloride solution. A white precipitate of barium sulfate means the original compound was a sulfate.
A: Rubidium and caesium.
A: A sophisticated flame test: substances are heated until they produce their own unique emission spectrum; used to detect very small amounts of elements.