1 Bongani is studying the postulates of Rutherford's atomic model. He learns that Rutherford proposed that the nucleus is positively charged. What did he conclude about the size of the nucleus? A The nucleus is very large compared to the atom B The nucleus is very small and dense compared to the atom C The nucleus is the same size as the atom D The nucleus does not exist
2 George is learning about radioisotopes. He understands that some isotopes are used in medicine for diagnosis and treatment. Which radioisotope is commonly used in medical imaging? A Uranium-238 B Carbon-14 C Technetium-99m D Chlorine-37
3 Emma is learning about the quantum mechanical model of the atom. Her teacher explains that it is the most accurate model. What is a key feature of the quantum mechanical model? A It describes electrons in terms of probability clouds or orbitals B It shows electrons moving in fixed circular paths C It says the nucleus is made of only protons D It ignores the wave nature of electrons
4 Fatima is studying the Heisenberg uncertainty principle. She learns that it states that we cannot know both the position and momentum of an electron with complete certainty. This principle applies to which model of the atom? A Dalton's model B Rutherford's model C Bohr's model D Quantum mechanical model
6 Paula is studying isotopes of chlorine. Chlorine has two common isotopes: chlorine-35 and chlorine-37. What is the difference between them? A Chlorine-37 has 2 more protons B Chlorine-37 has 2 more electrons C Chlorine-37 has 2 more neutrons D Chlorine-37 has 2 fewer neutrons
7 Usman is learning about the shell structure of atoms. He knows that the third shell (n=3) has three sub-shells: s, p, and d. What is the maximum number of electrons that can be held in the third shell? A 8 B 18 C 32 D 2
8 Mohamed is learning about isotopes. He understands that isotopes are atoms of the same element with different mass numbers. What is the reason for this difference? A Different number of protons B Different number of electrons C Different number of neutrons D Different number of nuclei
10 Which statement is true about electrons? A They are present in nucleus B They have mass equal to proton C They revolve around nucleus D They have positive charge
11 Usman is learning about electronic configuration. He understands that electrons are arranged in shells around the nucleus. What is the maximum number of electrons in the first shell (n=1)? A 2 B 8 C 18 D 32
12 The electronic configuration shows: A Arrangement of neutrons B Arrangement of protons C Arrangement of electrons D Arrangement of nucleus
16 Laura is learning about radioactivity. She discovers that some isotopes are unstable and emit radiation. What is the process called when an unstable nucleus emits particles and energy? A Nuclear fission B Radioactive decay C Nuclear fusion D Ionization
17 Which model replaced the idea of fixed electron paths? A Bohr model B Dalton model C Quantum mechanical model D Rutherford model
19 George is reviewing atomic structure. He knows that atoms consist of subatomic particles. Which of the following is NOT a subatomic particle found in an atom? A Proton B Electron C Neutron D Molecule
20 Hina is learning about the relationship between subatomic particles. She understands that protons and neutrons are located in the nucleus. What is the charge of a neutron? A Positive B Negative C Neutral D Both positive and negative
22 Xia is studying the history of atomic models. She learns that the quantum mechanical model is based on the wave-particle duality of electrons. Who proposed this concept? A Erwin Schrödinger B Niels Bohr C Ernest Rutherford D John Dalton
23 Waleed is learning about symbols for atoms and ions. He knows that the symbol for a sodium ion is Na+. What does the '+' sign indicate? A The atom has gained one electron B The atom has lost one electron C The atom has gained one proton D The atom has lost one proton
25 Zayn is studying relative atomic mass. He learns that chlorine has two isotopes: chlorine-35 (75% abundance) and chlorine-37 (25% abundance). What is the relative atomic mass of chlorine? A 35.0 amu B 35.5 amu C 37.0 amu D 36.0 amu