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Name: Ashley LawCollege ID: 0631739Thomas Edison State UniversityGeneral Chemistry I with Labs (CHE-121)Section no.: OL009Semester and year: June 2018Written Assignment 2: Atomic Structure and Chemical CompoundsAnswer all assigned questions and problems, and show all work. 1.What is the mass number of an iron atom that has 28 neutrons? (3 points)2.Calculate the number of neutrons of 239Pu. (3 points)239-94=145(Reference: Chang 2.14)3.Write the appropriate symbol for each of the following isotopes: (a) Z = 11, A = 23; (b) Z = 28, A = 64 (6 points)(a)²³Na¹¹ (b)Ni⁶⁴²⁸(Reference: Chang 2.17)4.Define, with two examples, the following terms: (a) alkali metals, (b) alkaline earth metal, (c) halogens, and (d) noble gases.(8 points)(a)Alkali metals are monovalent metals that are electropositive and is very reactive. Examples: Lithium and Sodium(b) Alkaline earth metals are bivalent strongly basic metals. Examples: Magnesium and Beryllium.