Q9.Hydrogen sulphide, H2S, is a simple molecular, covalent compound.(i) A hydrogen atom has one electron in its outer shell.A sulfur atom has six electrons in its outer shell.Which of the following is the dot and cross diagram of a molecule of hydrogen sulfide?(1)(ii) Which row in Figure 1 shows the properties of a simple molecular, covalent compound suchas hydrogen sulfide?(1)(Total for question = 2 marks)Q10.Covalent substances can be simple molecular covalent or giant covalent.Oxygen, O2, is also a simple molecular, covalent substance.Draw a dot and cross diagram for the molecule of oxygen.(2)(Total for question = 2 marks)Q11.The elements beryllium, magnesium, calcium, strontium and barium are in group 2 of theperiodic table.Barium has a melting point of 714 °C.Explain, in terms of structure and bonding, why barium has a high melting point.(3)..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(Total for question = 3 marks)Q12.Carbon dioxide is a simple molecular, covalent compound.It has a low boiling point of –78.5 °C.Explain why carbon dioxide has a low boiling point.(2)....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(Total for question = 2 marks)Q13.Which material is most suitable to make the electrodes for the electrolysis of a dilute acid?(1)A zincB sulfurC ironD graphite(Total for question = 1 mark)Q14.Magnesium oxide has a melting point of 2852 °C.Explain why magnesium oxide has such a high melting point.(3)..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(Total for question = 3 marks)Q15.A student used the equipment in Figure 2 to investigate whether electricity can pass throughsolid ammonium chloride and through ammonium chloride solution.If an electrical current flows in the circuit, the lamp will light up.Figure 3 shows the results of the investigation.Explain the results of the investigation.(3)..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(Total for question = 3 marks)