1 Which of the following scientist discovered neutron? flag bookmark A John Dalton B J. J Thomson C James Chadwick D Ernest Rutherford T4 Chapter 2.2 The Development of the Atomic Model James Chadwick discovered the neutron in 1932 through his experiments with beryllium and alpha particles.
2 Which of the following is the correct definition of relative atomic mass? flag bookmark A Average mass of one atom of the element ÷ The mass of one carbon-12 atom B Average mass of one atom of the element ÷ (12 × the mass of one carbon-12 atom) C Average mass of one atom of an element ÷ (1/12 × mass of one carbon-12 atom) D Mass of one carbon-12 atom ÷ (1/12 × average mass of one carbon-12 atom) T4 Chapter 3.1 Relative Atomic Mass and Relative Molecular Mass Relative atomic mass is the average mass of one atom of an element divided by 1/12 of the mass of one carbon-12 atom, so C is correct. Option B wrongly multiplies by 12 instead of taking one-twelfth.
3 How does the elements are arranged in the Periodic Table of Elements? flag bookmark A Descending order of atomic size B Ascending order of nucleon number C Descending order of number of neutron D Ascending order of proton number T4 Chapter 4.2 The Arrangement in the Periodic Table of Elements Elements are arranged in ascending order of proton number, which is the atomic number. This order determines each element's position and chemical properties.
4 Diagram 1 shows the electron arrangement of two compounds. Which of the following statement is true about the formation of chemical bond for both compounds? flag bookmark A Atoms of the elements form chemical bond through sharing or transfer of electrons B All atoms of elements can achieve stable duplet and octet electron arrangement C Atoms of the elements can form ionic bond through sharing of electrons D Atoms of the elements can form neutral molecules only T4 Chapter 5.1 Basics of Compound Formation Compound I forms ionic bonds by transferring electrons, while Compound II forms covalent bonds by sharing electrons. Hence, bonds are formed through either sharing or transfer of electrons.
5 Which of the following solutions with the same volume and concentration has the lowest number of hydroxide ions per unit volume? flag bookmark A Ammonia B Sodium hydroxide C Barium hydroxide D Calcium hydroxide T4 Chapter 6.3 Strength of Acids and Alkalis Ammonia is a weak base, so it only partially ionizes in water, producing fewer hydroxide ions than the strong bases at the same concentration.
6 The following chemical equation shows a reaction of ethene. > C₂H₄ + H₂ —(Ni, 180 °C)→ C₂H₆ Which of the following is true about nickel, Ni? flag bookmark A Change the rate of reaction and the quantity of the product B Change the rate of reaction and the quantity of reactants C Change the rate of reaction without undergoes physical changes D Change the rate of reaction without undergoes chemical changes T4 Chapter 7.2 Factors Affecting Rate of Reactions Nickel acts as a catalyst, speeding up the reaction without being chemically changed itself. It affects only the rate, not the amount of product or reactants.
7 Diagram 2 shows changes to the spectacles in two different situations. Which of the following substances are used to make the glass of the spectacles? I Silver chloride II Silver nitrate III Copper(I) chloride IV Copper(II) carbonate flag bookmark A I and II B I and III C II and IV D III and IV T4 Chapter 8.4 Composite Materials and Its Importance Photochromic lenses darken in sunlight using reversible reactions. Silver chloride and copper(I) chloride both change color under UV light, making them the correct substances.
8 Which of the following materials and characteristics are correctly matched? flag bookmark A Material: Alloy; Characteristic: Hard and resistance to corrosion B Material: Fibre glass; Characteristic: Can transmit data C Material: Superconductor; Characteristic: No electrical resistance at high temperature D Material: Reinforced concrete; Characteristic: Strong and can withstand high pressure T4 Chapter 8.1 Alloy and Its Importance Alloys are metals mixed to improve strength and hardness, and they resist corrosion well, so A is correct. Superconductors only have zero resistance at very low temperatures, not high.
9 Diagram 3 shows a half-cell. What is the function of platinum(IV) oxide in the cell? flag bookmark A Adsorbs oxygen gas B Acts as an inert electrode C Increases the surface area of platinum D Determine the standard hydrogen electrode value T5 Chapter 1.2 Standard Electrode Potential The platinum(IV) oxide coating increases the surface area of the platinum electrode, allowing more hydrogen gas to be adsorbed for the redox reaction.
10 Diagram 4 shows a chemical reaction involving long-chain hydrocarbon. What is reaction Q? flag bookmark A Fractional distillation B Polymerisation C Oxidation D Cracking T5 Chapter 2.1 Types of Carbon Compound Cracking breaks a long-chain alkane into a smaller alkane and an alkene, exactly as shown in the diagram.