Going down the group and left across the period, the atomic radii get bigger (excepting helium and hydrogen). In a sequence going from sodium to argon, you start with one valence electrons to eight valence electrons. Likewise, bromine will have a larger atomic radius when compared with chlorine. 3) Fe and Mg are in different periods. ). Magnesium is a light, silvery-white, and fairly tough metal. Atomic radius. Empirically measuring the radius of a single atom is a physically difficult task to accomplish and values vary from source to source. This alkaline earth metal has atomic number 12 and element symbol Mg. Now focus on potassium and bromine. describe and explain the trend in atomic radius down group 2; Atomic radius. Because they are light and strong, magnesium alloys are often used for tire rims. 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. Figure 1. Advanced Inorganic Chemistry (5th ed. Calcium(Ca) has 4 energy level while magnesium(Mg) has 3 Energy level. The table shows atomic radius values for the common elements in group 2 (the alkaline earth metals). Now, you have to decide between Fe and Mg which is larger. If you look on the period table you will notice Magnesium atomic number is 12, while Calcium is 20. Note: All measurements given are in picometers (pm). Magnesium. 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. ... Atomic Structure of Magnesium. All elements belong to period 3, but atomic radius decreases across the period due to increasing electronegativty. Na. The pattern, for elements in the same group is that the atomic radius increases … ii) Si and Mg are in the same period (3). Which of the following atoms has the largest atomic radius. 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: 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. Si is more to the right than Mg, so Mg is larger than Si. 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. 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. Atomic radii have been measured for elements. The atomic radius (r) of an atom can be defined as one half the distance (d) between two nuclei in a diatomic molecule. Chlorine AR: 100 pm . Magnesium AR: 150 pm . Because sodium is the first element in period 3, it has the largest radius. Magnesium is an element that is essential for human nutrition. Atomic radii used for this table were calculated values. The atomic radius is defined as one-half the distance between the nuclei of identical atoms that are bonded together. The pure element is a silver-colored metal, but it tarnishes in air to give it a dull appearance. These values were taken from these sources: Cotton, F. A.; Wilkinson, G. (1988). Calcium has a larger atomic radius than Magnesium.