Test: Year 10 Chemistry

Section A: Multiple Choice Questions (10 marks) Choose the correct answer from the options provided. Write the corresponding letter in the space provided.

1. Which of the following statements is true about atomic theory? a) Atoms are indivisible and cannot be broken down further. b) Atoms are made up of protons, neutrons, and electrons. c) Atoms of different elements have the same number of protons. d) Atoms of the same element can have different numbers of neutrons. e) Atoms are always positively charged.

2. The electronic configuration of an atom is determined by: a) The number of protons in the nucleus. b) The number of neutrons in the nucleus. c) The number of electrons in the outermost energy level. d) The number of electrons in the innermost energy level. e) The number of electrons in the nucleus.

3. Which of the following elements has the highest electronegativity? a) Sodium b) Chlorine c) Carbon d) Oxygen e) Hydrogen

4. Periodic trends refer to the patterns observed in: a) The atomic number of elements. b) The atomic mass of elements. c) The reactivity of elements. d) The boiling point of elements. e) The color of elements.

5. Metallic bonding is characterized by: a) Sharing of electrons between atoms. b) Transfer of electrons from one atom to another. c) Strong electrostatic attraction between positive ions and delocalized electrons. d) Weak forces of attraction between atoms. e) Formation of covalent bonds between atoms.

6. Which of the following elements is most likely to form a cation? a) Oxygen b) Fluorine c) Sodium d) Nitrogen e) Carbon

7. The atomic number of an element is determined by the number of: a) Protons in the nucleus. b) Neutrons in the nucleus. c) Electrons in the outermost energy level. d) Electrons in the innermost energy level. e) Electrons in the nucleus.

8. Which of the following elements is a halogen? a) Sodium b) Chlorine c) Calcium d) Iron e) Aluminum

9. The periodic table is arranged in order of increasing: a) Atomic mass. b) Atomic number. c) Electronegativity. d) Reactivity. e) Melting point.

10. Which of the following elements is a transition metal? a) Sodium b) Chlorine c) Iron d) Oxygen e) Carbon

Section B: Short Answer Questions (10 marks) Answer the following questions briefly and concisely.

1. Define atomic theory.
2. Explain the concept of electronic configuration.
3. What are periodic trends? Provide an example.
4. Describe metallic bonding and its properties.
5. How does the atomic number of an element determine its position in the periodic table?
6. Define electronegativity and explain its significance.
7. What is the difference between an element and a compound?
8. Explain the concept of valence electrons.
9. What is the significance of the outermost energy level in determining an element’s reactivity?
10. Define the term “transition metal” and provide an example.

Marking Scheme: Section A: Multiple Choice Questions (10 marks) 1. b) Atoms are made up of protons, neutrons, and electrons. 2. c) The number of electrons in the outermost energy level. 3. d) Oxygen 4. a) The atomic number of elements. 5. c) Strong electrostatic attraction between positive ions and delocalized electrons. 6. c) Sodium 7. a) Protons in the nucleus. 8. b) Chlorine 9. b) Atomic number. 10. c) Iron

Section B: Short Answer Questions (10 marks) 1. Atomic theory is the scientific theory that explains the nature and behavior of matter in terms of atoms. 2. Electronic configuration refers to the arrangement of electrons in the energy levels or shells of an atom. 3. Periodic trends are the patterns observed in the properties of elements as they are arranged in the periodic table. For example, the atomic radius generally decreases from left to right across a period. 4. Metallic bonding is the electrostatic attraction between positive metal ions and delocalized electrons. It gives metals their characteristic properties such as malleability, ductility, and high electrical conductivity. 5. The atomic number of an element determines its position in the periodic table because the elements are arranged in order of increasing atomic number. 6. Electronegativity is the measure of an atom’s ability to attract electrons towards itself in a chemical bond. It is significant in determining the type of bond formed between atoms. 7. An element is a pure substance made up of only one type of atom, while a compound is a substance made up of two or more different types of atoms chemically bonded together. 8. Valence electrons are the electrons in the outermost energy level of an atom. They are involved in chemical bonding and determine the reactivity of an element. 9. The outermost energy level determines an element’s reactivity because it determines the number of valence electrons, which are involved in chemical reactions. 10. Transition metals are elements that have partially filled d orbitals in their electron configuration. They are located in the middle of the periodic table and exhibit variable oxidation states. An example of a transition metal is iron (Fe).

Solutions: Section A: Multiple Choice Questions 1. b) Atoms are made up of protons, neutrons, and electrons. 2. c) The number of electrons in the outermost energy level. 3. d) Oxygen 4. a) The atomic number of elements. 5. c) Strong electrostatic attraction between positive ions and delocalized electrons. 6. c) Sodium 7. a) Protons in the nucleus. 8. b) Chlorine 9. b) Atomic number. 10. c) Iron

Section B: Short Answer Questions 1. Atomic theory is the scientific theory that explains the nature and behavior of matter in terms of atoms. 2. Electronic configuration refers to the arrangement of electrons in the energy levels or shells of an atom. 3. Periodic trends are the patterns observed in the properties of elements as they are arranged in the periodic table. For example, the atomic radius generally decreases from left to right across a period. 4. Metallic bonding is the electrostatic attraction between positive metal ions and delocalized electrons. It gives metals their characteristic properties such as malleability, ductility, and high electrical conductivity. 5. The atomic number of an element determines its position in the periodic table because the elements are arranged in order of increasing atomic number. 6. Electronegativity is the measure of an atom’s ability to attract electrons towards itself in a chemical bond. It is significant in determining the type of bond formed between atoms. 7. An element is a pure substance made up of only one type of atom, while a compound is a substance made up of two or more different types of atoms chemically bonded together. 8. Valence electrons are the electrons in the outermost energy level of an atom. They are involved in chemical bonding and determine the reactivity of an element. 9. The outermost energy level determines an element’s reactivity because it determines the number of valence electrons, which are involved in chemical reactions. 10. Transition metals are elements that have partially filled d orbitals in their electron configuration. They are located in the middle of the periodic table and exhibit variable oxidation states. An example of a transition metal is iron (Fe).