2 For an atom of carbon with symbol 12/6 C, the atomic number (Z) and number of electrons are: A 12 and 12 B 6 and 12 C 12 and 6 D 6 and 6
3 Which property of metals is due to the mobility of delocalized electrons? A Malleability B Ductility C Electrical conductivity D High melting point
4 Which of the following molecules can form hydrogen bonds? A Methane (CH4) B Ammonia (NH3) C Carbon dioxide (CO2) D Chlorine (Cl2)
5 Which allotrope of carbon is the hardest natural substance? A Graphite B Diamond C Fullerene D Charcoal
6 The Tyndall effect is observed in: A True solutions B Colloidal solutions C Suspensions only D Pure liquids
7 The particles of a colloidal solution are of size: A less than 1 nm B between 1 nm and 1000 nm C more than 1000 nm D exactly 1 nm
8 In a balanced chemical equation, the number of atoms of each element on both sides is: A equal B different C greater on reactant side D greater on product side
9 What is the approximate particle size of a colloidal solution? A Less than 1 nm B 1 nm to 1000 nm C More than 1000 nm D Exactly 1 cm
10 The isotope of hydrogen that has one proton and two neutrons is called: A Protium B Deuterium C Tritium D Hydride
11 In a mass spectrometer, ions are separated based on their: A Charge only B Mass only C Mass-to-charge ratio (m/e) D Color
12 The mass number (A) of an atom is equal to the number of: A Protons only B Neutrons only C Protons plus neutrons D Protons plus electrons
13 How does the solubility of most solids change with an increase in temperature? A It decreases B It increases C It remains the same D It first decreases then increases
14 The mass of one mole of a substance is called its: A Molar mass B Molecular mass C Empirical mass D Formula mass
16 The number of electrons in a neutral atom is equal to its: A Mass number B Atomic number C Number of neutrons D Mass number minus atomic number
17 On a solubility curve, the region below the curve represents: A Saturated solution B Unsaturated solution C Supersaturated solution D Colloidal solution
18 In the reaction 2H2 + O2 → 2H2O, if 4 moles of H2 react with excess O2, how many moles of H2O are produced? A 4 moles B 2 moles C 1 mole D 8 moles
21 The relative atomic mass of an element is calculated with reference to which standard? A Carbon-12 B Hydrogen-1 C Oxygen-16 D Chlorine-35
22 Which branch of chemistry studies the composition and structure of substances? A Physical chemistry B Analytical chemistry C Polymer chemistry D Nuclear chemistry
23 In a covalent bond, electrons are: A Transferred completely B Shared between atoms C Lost by both atoms D Gained by both atoms
24 The strength of metallic bond depends on: A Number of delocalised electrons and size of metal ions B Number of protons in the nucleus C Number of neutrons in the nucleus D Presence of hydrogen bonds
25 The relative atomic mass of chlorine is 35.5 because it consists of: A Only chlorine-35 B Only chlorine-37 C A mixture of chlorine-35 and chlorine-37 D Equal numbers of protons and neutrons