1) Which of the following gives the description of the quantum-mechanical model of the atom? I. It describes an electron probability distribution that determines the most likely location of an electron. II. It is the currently accepted atomic model. III. It explains the emission spectra of hydrogen atoms. IV. It makes predictions based on Schrodinger’s wave equation. a) I b) II c) I, II, & III d) I, II & IV 2) These all are the characteristics of ionic compounds EXCEPT. a) Soft b) Conduct electricity when dissolved in water c) High melting and boiling points d) Crystal lattice structure 3) Why do ionic compounds have such high melting and boiling points? a) The electrostatic forces of attraction between the positive and negative ions holding the lattice together are very strong and a lot of energy is required to break them apart. b) The electrostatic forces of attraction between the positive ions holding the lattice together are very strong and a lot of energy is required to break them apart. c) The electrostatic forces of attraction between the positive and electrons holding the lattice together are very strong and a lot of energy is required to break them apart. d) The electrostatic forces of attraction between the cations and anions holding the lattice together are very weak and a less energy is required to break them apart. 4) The diagram beside shows the transfer of electron between the elements K and Cl forming Potassium Chloride commonly known as salt that can be used as a medication to treat low potassium levels in the blood through ionic bond. I. Transfer of electron is taking place. II. A strong attraction between a metal and a nonmetal is formed. III. There is a strong attraction between two non-metallic elements. IV. It is formed if the electronegativity difference is greater than 1.9 V. An element tends to gain a charge by losing or gaining electrons after the bond formation. a) I,II,III & IV only b) I,II,IV & V only c) I,III, IV & V only d) I,II,III & V only 5) How does ionic bonding take place? a) Two non-metallic elements of the same kind form strong forces of attraction. b) Two non-metallic elements of different kinds form strong forces of attraction. c) A non-metallic element like fluorine is attracted to a metallic element like sodium. d) A metallic element like silicon transfers an electron to a non-metallic element like magnesium. 6) Which of the following best describes the carbon bond type shown in the diagram below? = = C = = a) Two double bonds, each sharing 2 valence electrons with an atom b) Two double bonds, each sharing 8 valence electrons with an atom c) Two double bonds, each sharing 6 valence electrons with an atom d) Two double bonds, each sharing 4 valence electrons with an atom 7) What are the three basic groups of hydrocarbon compounds? a) Alkanes, Alkenes, Alkynes b) Acetone, Acetylene, Alcohol c) Butane, Butene, Butyne d) Carbonyl, hydroxyl, Carbide 8) A bag of NPK fertilizer marked 16-4-8 contains 16% nitrogen, 4% phosphorous and 8% potassium and the other 72% is usually inert filler material, such as clay pellets or granular limestone. What is the mass of nitrogen present in the 500g pack of NPK fertilizer? a) 10g b) 40g c) 20g d) 80g 9) An element tends to gain a charge by losing or gaining electrons after the bond formation. a) % C= 19.99 % b) % C= 39.99 % c) % C= 29.99 % d) % C= 49.99 % 10) Find the molecular mass of glucose, which has a molecular formula (C6 H12 O6)? a) 160.16 b) 180.16 c) 190.16 d) 192.16 11) Which among the following shows that an atom is stable? a) Having 2 valence electrons b) Having 4 valence electrons c) Having 6 valence electrons d) Having 8 valence electrons 12) Which of the following types of atoms composed a covalent bond? a) Both metals b) Metals and non-metals c) Both non-metals d) Metalloids 13) How did the valence electrons in a covalent compound achieve the octet? a) by losing and gaining electrons b) by sharing electrons c) by reducing the electron’s weight by half d) All of the above 14) Which element will most likely gain an electron and acquire a negative charge between the element combination Li and F? a) F b) Li c) both elements will have a negative charge d) none of these 15) What is the maximum number of bonds a carbon atom can form? a) 2 b) 3 c) 4 d) 5

DAT 2022 Review for G9 Science in Quarter 2

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