Advanced Inorganic Chemistry (5th ed. The electron configuration of magnesium and aluminium are given below: Al(13)= 1s2 2s2 2p6 3s2 3p1 Mg(12)= 1s2 2s2 2p6 3s2 Al has 13 protons and 3 electrons in the outermost energy level. Empirically measuring the radius of a single atom is a physically difficult task to accomplish and values vary from source to source. The table shows atomic radius values for the common elements in group 2 (the alkaline earth metals). These values were taken from these sources: Cotton, F. A.; Wilkinson, G. (1988). Now focus on potassium and bromine. Because sodium is the first element in period 3, it has the largest radius. Figure 1. Na. Atomic radii have been measured for elements. The pure element is a silver-colored metal, but it tarnishes in air to give it a dull appearance. Since potassium is located at the start of period 3, and bromine at the end of the same period, potassium will have a larger atomic radius than bromine, and thus the largest atomic radius of the four given atoms. ). Likewise, bromine will have a larger atomic radius when compared with chlorine. Si is more to the right than Mg, so Mg is larger than Si. If you look on the period table you will notice Magnesium atomic number is 12, while Calcium is 20. Chlorine AR: 100 pm . Going down the group and left across the period, the atomic radii get bigger (excepting helium and hydrogen). Because they are light and strong, magnesium alloys are often used for tire rims. All elements belong to period 3, but atomic radius decreases across the period due to increasing electronegativty. Atomic radii used for this table were calculated values. Magnesium. ... Atomic Structure of Magnesium. Which of the following atoms has the largest atomic radius. Magnesium is a light, silvery-white, and fairly tough metal. a. Barium (Ba) b. Chlorine (CI) c. lodine (1) d. Magnesium (Mg) ...” in Chemistry if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions. 3) Fe and Mg are in different periods. Atomic radius. Magnesium AR: 150 pm . Note: All measurements given are in picometers (pm). The atomic radius is defined as one-half the distance between the nuclei of identical atoms that are bonded together. Atomic Number: 12: Atomic Radius: 173 pm (Van der Waals) Atomic Symbol: Mg: Melting Point: 650 °C: Atomic Weight: 24.31: Boiling Point: 1091 °C: Electron Configuration: [Ne]3s 2: ii) Si and Mg are in the same period (3). Calcium has a larger atomic radius than Magnesium. Now, you have to decide between Fe and Mg which is larger. Calcium(Ca) has 4 energy level while magnesium(Mg) has 3 Energy level. describe and explain the trend in atomic radius down group 2; Atomic radius. The pattern, for elements in the same group is that the atomic radius increases … Comprehensive information for the element Magnesium - Mg is provided by this page including scores of properties, element names in many languages, most known nuclides and technical terms are linked to their definitions. In a sequence going from sodium to argon, you start with one valence electrons to eight valence electrons. This alkaline earth metal has atomic number 12 and element symbol Mg. The atomic radius (r) of an atom can be defined as one half the distance (d) between two nuclei in a diatomic molecule. For more recent data on covalent radii see Covalent radius.Just as atomic units are given in terms of the atomic mass unit (approximately the proton mass), the physically appropriate unit of length here is the Bohr radius, which is the radius of a hydrogen atom. Magnesium is an element that is essential for human nutrition.