1. Complete the following table: (a) Name element X. (b) Which of the above elements is/are metal? (c) State the Group and Period of the element Y. (d) 2. Element Q has two isotopes of mass number 28 and 30 respectively. The percentage abundance of the isotope with mass number 28 is 12.8%. (a) Define the term "isotope". (b) Calculate the relative atomic mass of Q. (4 marks) 3. The table below shows the electronic arrangement of four element a,b,c and d. (a) a and d belong to same group. (i) Which group does element a and d belong to? Give the group name. (ii) What is the no. of " y " in element d ? Explain. (b) (i) Which of them is a chemically inert element? (ii) Draw the electron diagram of this element. ( 6 marks)