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The atomic symbol “Al” tells us: Element: The element is Aluminum. Atomic Number: Aluminum has an atomic number of 13, meaning it has 13 protons and 13 electrons in a neutral atom. Mass Number: The mass number (atomic mass) can be deduced from the isotope being referenced, typically 27 for the most common isotope of … Read more
(a) How many protons and electrons does an atom of this element have? Protons: The atomic number is 23, so it has 23 protons. Electrons: In a neutral atom, the number of electrons equals the number of protons, so it has 23 electrons. (b) How many neutrons does this atom have? Neutrons = Mass number … Read more
Medicine: Radioactive isotopes are used for medical imaging and cancer treatment (e.g., iodine-131 for thyroid cancer). Dating: Carbon-14 is used in radiocarbon dating to estimate the age of ancient artifacts and fossils. Energy: Uranium-235 and plutonium-239 are used as fuel in nuclear reactors. Agriculture: Isotopes are used to track the movement of nutrients in plants … Read more
(a) Si (Silicon, Atomic Number 14) 1s² 2s² 2p⁶ 3s² 3p² (b) Mg (Magnesium, Atomic Number 12) 1s² 2s² 2p⁶ 3s² (c) Ar (Argon, Atomic Number 18) 1s² 2s² 2p⁶ 3s² 3p⁶ Related Questions: The electronic configurations listed below are incorrect. Explain the mistakes in each and write the correct electronic configurations. Draw Bohr’s Model … Read more
(a) Potassium (Atomic No. 19, Mass No. 39) Protons: 19 Neutrons: 39 – 19 = 20 Electrons: 19 The Bohr model would show 19 electrons arranged in 4 shells: K shell (1s): 2 electrons L shell (2s, 2p): 8 electrons M shell (3s, 3p): 8 electrons N shell (4s): 1 electron (b) Silicon (Atomic No. … Read more
z = 1s, 2s, 2p, 3s’ Mistake: The configuration ends with 3s’, which is incorrect because the electron configuration of the 3rd shell should fill the 3s sub-shell first before moving to higher sub-shells such as 3p. Correct configuration: 1s² 2s² 2p⁶ 3s² x = 1s, 2s, 2p’, 3p’ Mistake: The configuration mentions 2p’ and … Read more