q1 chemistry: u2l3 isotopes\nprework part 2: average atomic mass\ndirections: read the passage below. as you…

q1 chemistry: u2l3 isotopes\nprework part 2: average atomic mass\ndirections: read the passage below. as you read, annotate the important information and vocabulary words. then answer the questions.\n**part 1: read & annotate:\nwhat is average atomic mass?\nevery element on the periodic table has an atomic mass listed beneath its symbol. this number is not usually a whole number because it represents the average atomic mass, not the mass of a single atom.\nthe average atomic mass is calculated by considering the different isotopes of an element and their relative abundance—how common each isotope is in nature. since isotopes of the same element have different numbers of neutrons, they have different masses. the average atomic mass is a weighted average, not a simple average, and it reflects the contribution of each isotope based on how much of it is found naturally.\nfor example, chlorine has two major isotopes:\n- chlorine - 35 (mass = 35 amu, abundance = 75%)\n- chlorine - 37 (mass = 37 amu, abundance = 25%)\nthe average atomic mass of chlorine is: note: the percentages are converted to decimal before plugging them into the formula: (ex: 75% = 0.75)\n(35×0.75)+(37×0.25)=26.25 + 9.25 = 35.5 amu\nthe average atomic mass will be closest to the isotope with the greatest percent abundance. the average atomic mass for chlorine is 35.5 amu which is closest to 35 because chlorine - 35 has 75% abundance in nature.\n**part 2: calculation\ndirections: use the information below to calculate the average atomic mass of the given elements.\nelement isotope (mass) & percent abundance average atomic mass (amu)\nmagnesium 24 (78.99%), 25 (10.00%), 26 (11.01%)\npart 3: reflection questions\n1. why is the average atomic mass rarely a whole number?\n2. what information do you need to calculate the average atomic mass of an element?

Answer