Most Important Chemistry Mcqs 21- What is the atomic number of an element with 12 protons ? A. 6B. 12C. 18D. 24 View Answer Answer : B. 12 Description 22- How many neutrons are in an atom of Carbon-14 ? A. 6B. 8C. 14D. 20 View Answer Answer : B. 8 Description 23- Which particle determines the identity of an element ? A. PositronB. ElectronC. NeutronD. Proton View Answer Answer : D. Proton Description 24- What is the maximum number of electrons in the 4th energy level ? A. 8B. 18C. 32D. 50 View Answer Answer : C. 32 Description 25- Which sublevel has the highest energy in the 3rd shell ? A. 3dB. 3sC. 3pD. 3f View Answer Answer : A. 3d Description 26- What is the electron configuration of Nitrogen (N) ? A. 1s² 2s² 2p³B. 1s² 2s² 2p⁶ C. 1s² 2s² 2p⁵ D. 1s² 2s² 2p⁴ View Answer Answer : A. 1s² 2s² 2p³ Description 27- Which quantum number describes the shape of an orbital ? A. Principal (n) B. Azimuthal (l)C. Magnetic (m)D. Spin (s) View Answer Answer : B. Azimuthal (l) Description 28- What is the charge of a proton ? A. -1B. 0C. +1D. +2 View Answer Answer : C. +1 Description 29- What is the mass number of an atom with 6 protons and 8 neutrons ? A. 6B. 8C. 12D. 14 View Answer Answer : D. 14 Description 30- Which of the following is an isotope of Hydrogen ? A. TritiumB. DeuteriumC. Both A and BD. None of these View Answer Answer : C. Both A and B Description 31- What is the shape of an s-orbital ? A. SphericalB. DumbbellC. CloverleafD. Complex View Answer Answer : A. Spherical Description 32- How many orbitals are in the p-sublevel ? A. 1B. 3C. 5D. 7 View Answer Answer : B. 3 Description 33- What is the maximum number of electrons in a d-sublevel ? A. 2B. 6C. 10D. 14 View Answer Answer : C. 10 Description 34- Which element has the electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ ? A. Magnesium (Mg) B. Calcium (Ca)C. Sodium (Na)D. Potassium (K) View Answer Answer : D. Potassium (K) Description 35- What is the charge of an electron ? A. OB. -1C. +1D. +2 View Answer Answer : B. -1 Description 36- Which of the following is NOT a fundamental particle of an atom ? A. ProtonB. NeutronC. ElectronD. Photon View Answer Answer : D. Photon Description 37- What is the atomic number of Oxygen ? A. 6B. 8C. 10D. 16 View Answer Answer : B. 8 Description 38- Which of the following is true about isotopes ? A. Same atomic number, different mass numberB. Same mass number, different atomic numberC. Same number of neutrons, different protonsD. Same number of protons, different electrons View Answer Answer : A. Same atomic number, different mass number Description 39- What is the maximum number of electrons in the 2nd energy level ? A. 2B. 8C. 18D. 32 View Answer Answer : B. 8 Description 40- Which element has the smallest atomic radius ? A. HydrogenB. LithiumC. FluorineD. Helium View Answer Answer : D. Helium Description 1 2 3 4 5
