5 Usman is studying metallic bonds. He learns that metals have a 'sea of delocalized electrons'. What is the characteristic of metallic bonding that explains the conductivity of metals? A Presence of free ions B Presence of a sea of free electrons C Presence of covalent bonds D Presence of ionic bonds
8 Diana is studying the conductivity of graphite. She learns that graphite is a good conductor of electricity, while diamond is not. Why does graphite conduct electricity? A Because it has free ions B Because it has delocalized electrons within the layers C Because it has a metallic bond D Because it has hydrogen bonding
9 Carlos is learning about the structure of graphite and diamond. He knows that both are allotropes of carbon. What is the key difference in the bonding of graphite and diamond? A Diamond has ionic bonds, graphite has covalent bonds B Diamond has a three-dimensional covalent network, graphite has layers with weak forces C Graphite has metallic bonds, diamond has covalent bonds D Both have the same bonding
10 Ibrahim is learning about coordinate covalent bonds. He understands that in this type of bond, both electrons are supplied by one atom. Which of the following involves a coordinate covalent bond? A NH4+ B NaCl C MgO D Al2O3
11 Qasim is learning about the uses of graphite. He understands that graphite is used as a lubricant. Why is graphite a good lubricant? A Because it is very hard B Because layers can slide over each other easily C Because it is a good conductor of electricity D Because it is chemically inert
12 Omar is studying metallic bonds. He understands that the 'sea of electrons' model explains many properties of metals. Which property is explained by the mobility of electrons in metals? A High melting point B Electrical conductivity C Ductility D Malleability
13 Ethan is learning about polar and non-polar molecules. He knows that polar molecules have a dipole moment. Which of the following molecules is non-polar? A HCl B H2O C CO2 D NH3
15 Hina is studying hydrogen bonding. She learns that hydrogen bonding is responsible for many properties of water. What property of water is due to hydrogen bonding? A Low boiling point B High surface tension C Non-polarity D Low viscosity
17 Waleed is studying industrial uses of metals. He learns that copper is used in electrical wiring. Why is copper suitable for this purpose? A Because it is very strong B Because it is a good conductor of electricity and is ductile C Because it is very cheap D Because it is chemically very reactive
18 Chemical bonding helps to explain: A Weather changes B Physical and chemical properties C Biological growth D Gravity
19 Mohamed is learning about the condition of electricity in ionic compounds. He knows that ionic compounds conduct electricity in certain states. In which state do ionic compounds conduct electricity? A Solid state B Molten or aqueous state C Gaseous state D Vapor state
20 Laura is studying the structure of diamond. She learns that diamond is made of carbon atoms, each bonded to four other carbon atoms. What type of structure does this form? A A layered structure B A three-dimensional network C A chain structure D A ring structure
21 David is studying electropositive and electronegative elements. He learns that electropositive elements tend to lose electrons. Which of the following is an electropositive element? A Chlorine B Oxygen C Sodium D Nitrogen
22 Bonding between atoms determines: A Atomic number B Color only C Properties of substances D Neutron number
23 Chloe is learning about chemical bonds. She understands that bonds form when atoms gain, lose, or share electrons. Which type of bond is formed when electrons are transferred from one atom to another? A Covalent bond B Ionic bond C Metallic bond D Hydrogen bond
24 Yara is studying the properties of ionic and covalent compounds. She learns that ionic compounds have high melting points and dissolve in water to form electrolytes. Which of the following is an electrolyte? A Sugar B Glucose C Sodium chloride D Methanol
25 George is learning about double and triple covalent bonds. He knows that multiple bonds involve sharing more than one pair of electrons. Which molecule contains a triple covalent bond? A O2 B N2 C Cl2 D CH4