1 Atomic size generally decreases across a period from left to right because: A Nuclear charge increases and shells remain same B Number of shells increases C Atomic mass decreases D Number of neutrons decreases
2 Which practice reduces parallax error when reading a burette? A Reading the top of the meniscus B Keeping the eye level with the meniscus C Reading from below the meniscus D Reading from far away
3 What is the process of breaking large hydrocarbon molecules into smaller ones called? A Combustion B Cracking C Substitution D Addition
4 Which fire extinguisher is suitable for electrical fires? A Water extinguisher B Foam extinguisher C Carbon dioxide extinguisher D Sand bucket
5 A student records the following readings: 5.1 g, 5.2 g, 5.0 g. The true value is 5.1 g. Which statement is correct? A The readings are precise but not accurate B The readings are accurate but not precise C The readings are both accurate and precise D The readings are neither accurate nor precise
8 Which PPE protects your hands from corrosive chemicals? A Gloves B Safety goggles C Lab coat D Closed shoes
9 Which of the following is a characteristic property of Group 1 elements (alkali metals) when they react with water? A They produce hydrogen gas and form an alkaline solution. B They produce oxygen gas and form an acidic solution. C They produce carbon dioxide gas and form a neutral solution. D They do not react with water.
10 Which of the following is not a use of alkanes? A Fuel B Lubricant C Preparation of polymers D As a solvent
11 Which of the following is a property of metals? A They are brittle B They are good conductors of heat and electricity C They have low melting points D They are non-lustrous
12 As we move down a group in the periodic table, the atomic size generally: A Increases B Decreases C Remains the same D First decreases then increases
13 In which layer of the atmosphere does weather mostly occur? A Troposphere B Stratosphere C Mesosphere D Thermosphere
15 Which scientist arranged the elements in the modern periodic table on the basis of atomic number? A Mendeleev B Moseley C Dalton D Rutherford
16 Which gas is present in the highest percentage in the Earth's atmosphere? A Oxygen B Nitrogen C Carbon dioxide D Argon
17 Which method helps reduce air pollution from vehicles? A Burning more coal B Using catalytic converters C Cutting down trees D Increasing factory smoke
18 Which statement defines precision? A How close repeated measurements are to each other B How close a measurement is to the true value C How costly the instrument is D How quickly the measurement is taken
20 Which hazard sign warns about materials that may explode? A Explosive B Irritant C Corrosive D Health hazard
21 What does an oxidising hazard sign indicate? A The chemical can supply oxygen and intensify fire B The chemical is safe C The chemical is corrosive D The chemical is toxic
22 Elements in the same group of the periodic table have the same number of: A Neutrons B Valence electrons C Protons D Shells
23 After using PPE, what is the correct disposal practice for gloves? A Dispose of them in the designated waste bin B Wash and reuse them always C Throw them on the floor D Put them in a chemical bottle
24 What does the radiation hazard symbol warn about? A Presence of radioactive materials B Presence of toxic gases C Presence of flammable liquids D Presence of corrosive acids
25 The combustion of alkanes in excess oxygen produces: A Carbon monoxide and water B Carbon dioxide and water C Carbon and hydrogen D Only carbon dioxide