9. Metals
A section of Chemistry, 0620
Listing 10 of 1272 questions
The table shows some properties of four GroupI elements. element melting point / °C boiling point / °C atomic radius / nm sodium 0.191 potassium rubidium 0.250 caesium 0.272 Complete the table by predicting: ● the boiling point of rubidium ● the atomic radius of potassium.  Describe the trend in the melting point of the GroupI elements down the group. Deduce the physical state of potassium at 60 °C. Explain your answer. Caesium is a radioactive element with a proton number of 55. Define proton number. State one industrial use of radioactive isotopes. Sodiumhydride, NaH, reacts with iron(oxide. Balance the equation for this reaction. Fe2O3 + 3NaH → Fe + NaOH Explain how this equation shows that iron(oxide is reduced. 
0620_s21_qp_31
THEORY
2021
Paper 3, Variant 1
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Cement is made by heating a mixture of calciumcarbonate and powdered clay. Choose from the list the name of the substance which contains calciumcarbonate. Draw a circle around the correct answer. bauxite hematite limestone slaked lime The heat for this process is provided by burning natural gas. Name the main constituent of natural gas. Complete the word equation for the thermal decomposition of calcium carbonate. calcium carbonate +  Carbon dioxide is produced when dilute hydrochloric acid reacts with powdered calciumcarbonate. CaCO3 + 2HCl → CaCl 2 + CO2 + H2O Complete the diagram to show the apparatus used to investigate the volume of carbondioxide produced during this reaction. water M  Name the piece of apparatus labelled M in the diagram. Suggest the name of another piece of apparatus that can be used to measure the volume of carbondioxide produced. Describe the effect of each of the following on the rate of reaction of dilute hydrochloricacid with calciumcarbonate. ● Large pieces of calciumcarbonate are used instead of powdered calciumcarbonate. All other conditions stay the same. ● The temperature is decreased. All other conditions stay the same.  Explain how carbondioxide contributes to climate change. 
0620_s21_qp_33
THEORY
2021
Paper 3, Variant 3
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Silver has an atomic number of 47. Naturally occurring atoms of silver are 107Ag and 109Ag. State the name given to atoms of the same element with different nucleon numbers. Complete the table to show the number of protons, neutrons and electrons in each atom and ion of silver shown. 107Ag 109Ag+ protons neutrons electrons  Complete this definition of relative atomic mass. Relative atomic mass is the mass of naturally occurring atoms of an element on a scale where the atom has a mass of exactly units.  A sample of silver has a relative atomic mass of 108.0. Deduce the percentage of 107Ag present in this sample of silver. Silvernitrate is a salt of silver made by reacting silveroxide with an acid. Write the formula of the acid which reacts with silveroxide to form silvernitrate. Aqueous silvernitrate is a colourless solution containing Ag+ions. Describe what is seen when aqueous silvernitrate is added to aqueous sodiumiodide, NaI. Write the ionic equation for the reaction between aqueous silver nitrate and aqueous sodium iodide. Include state symbols. In the positive test for aqueous nitrate ions, aqueous sodiumhydroxide and one other substance are warmed with the nitrate ions. Name this other substance and the gas formed. name of substance name of gas  When silvernitrate is exposed to sunlight, silver is formed. Name the type of reaction which needs light to make it happen. Members of one homologous series only react with chlorine in the presence of sunlight. Name a member of this homologous series. Name two products that form when the compound in reacts with chlorine.  
0620_s21_qp_42
THEORY
2021
Paper 4, Variant 2
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