Organisation of the periodic tableIB MYP Sciences: Subtopic test

1. 1
   A school in Kuala Lumpur prints a large periodic table for its laboratory wall. Students use it to find the symbol, the group and the period of each element, and to decide whether an element is a metal, a non-metal or a metalloid.

   (a)

   Which row gives the correct chemical symbols for potassium, iron and copper, in that order?

   [1 mark]

   • AP, Fe, Cu
   • BK, Fe, Cu
   • CK, Ir, Co
   • DPo, Fe, Cr

   (b)

   Which of these elements is a metalloid?

   [1 mark]

   • ASilicon
   • BSodium
   • CSulfur
   • DNeon

   (c)

   Describe where metals and non-metals are found in the periodic table.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student is making his own copy of the periodic table. He has a card for each element showing only its electron configuration, for example fluorine 2,7 and chlorine 2,8,7, and he places each card in the group and period that its electrons indicate.

   (a)

   Which statement is true of all the elements in the same group of the periodic table?

   [1 mark]

   • AThey have the same number of electron shells
   • BThey have the same atomic number
   • CThey have the same number of outer electrons
   • DThey have the same relative atomic mass

   (b)

   Which element is in the same period as sodium, which has the configuration 2,8,1?

   [1 mark]

   • ALithium, 2,1
   • BPotassium, 2,8,8,1
   • CFluorine, 2,7
   • DChlorine, 2,8,7

   (c)

   Explain why fluorine and chlorine are placed in the same group but in different periods.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   In 1869 Dmitri Mendeleev arranged the 63 elements known at the time in order of increasing atomic mass, but moved a few so that elements with similar properties fell in the same column. He also left gaps for elements that had not yet been discovered. He predicted that the missing element below silicon would have a relative atomic mass of about 72, a density of about 5.5 g/cm³, a grey colour and an oxide with the formula XO₂. In 1886 germanium was discovered. It has a relative atomic mass of 72.6, a density of 5.35 g/cm³, a grey colour and an oxide with the formula GeO₂.

   (a)

   Describe how Mendeleev organised his periodic table, and why he left gaps in it.

   [3 marks]

   (b)

   Evaluate how well the discovery of germanium supports Mendeleev's periodic table.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A team of engineers in Seoul is designing solar panels and computer chips. They use silicon, which has the electron configuration 2,8,4 and is a metalloid in the periodic table. Silicon is a semiconductor, meaning that it conducts electricity only under some conditions. It is made from sand by heating it to very high temperatures in electric furnaces. The engineers also compare silicon with aluminium (2,8,3), a metal, and sulfur (2,8,6), a non-metal.

   (a)

   Explain why silicon is classed as a metalloid and how its position in the periodic table is linked to its electron configuration.

   [6 marks]

   (b)

   Discuss and evaluate the use of silicon to make solar panels and computer chips.

   [6 marks]

   Total for question 4: 12 marks

End of questions