magnesium has three common isotopes

A dose of children's medication was prescribed to be 5.0 teaspoons (tsp). For example, carbon has six protons and is atomic number 6. A. An element has the following natural abundances and isotopic masses: 90.92% abundance with 19.99 amu, 0.26% abundance with 20.99 amu, and 8.82% abundance with 21.99 amu. Isotope 1 is found to have an isotopic mass of 38.9637 amu and a natural abundance of 93.258%. The information contained in this website is for general information purposes only. The three share the place in the periodic table assigned to atomic number 1 and hence are called isotopes (from the Greek isos, meaning "same," and topos, signifying "place") of hydrogen. The atomic weight is 151.9641 amu. If you have any questions or comments, please dont hesitate to contact us. Magnesium has three stable isotopes, Mg-24, Mg-25, Mg-26. The mass of Isotope 1 (24.342% abundant) and Isotope 2 (56.021% abundant) are 11.089435 amu and 18.150090 amu, respectively. How many grams of NaOH will react completely with 296 mL of 0.250 M HCl? Calculate the atomic mass of magnesium giving the following information: Isotope: ^{24}Mg Abundance (%): 78.90 Isotope Mass (amu): 23.9850 Isotope: ^{25}Mg Abundance (%): 10.00 Isotope Mass (amu): 24.9858 Isotope: ^{26}Mg Abundance (%): 11.10 Isotope Ma. Magnesium has three common isotopes. Chemistry College answered expert verified The element magnesium, Mg, has three common isotopes:24Mg, 25Mg, and 26Mg. what is the parent and molecular structure of O3? Q: When strontium (Sr), rubidium (Rb), magnesium (Mg) and sodium (Na) are arranged in order of A: Given : elements Tip : 1.atomic size increases on moving top to bottom in periodic table 2.atomic It is thePauli exclusion principlethat requires the electrons in an atom to occupy different energy levels instead of them all condensing in the ground state. Just based upon how updated the periodic table is because these atomic masses are constantly being tweaked and updated. 21 carbon atoms, 32 hydrogen atoms, 2 nitrogen atoms, and 1 oxygen atom. bonding electrons are unequally shared in a polar covalent bond. These isotopes are Mg--22, Mg23, Mg-27, Mg-28, and Mg-29. In nature, "Valentinium" consists of two isotopes, Valentinium-69 (Mass = 68.926 with natural abundance of 60.1%) and Valentinium-71 (Mass = 70.925 with natural abundance of 39.9%). What would be the isotopic symbol for the element argon that contains 22 neutrons? An element has two naturally occurring isotopes. Naturally occurring chlorine has two isotopes, Cl-35, which has an atomic mass of 34.969 amu and Cl-37. A large order of McDonald's French Fries has a total mass of 168g and 24g of fat. atomic mass: Hi in this question, we are asked to calculate the average atomic mass of magnesium and while it says average the average, when you're talking about an atomic mass is a weighted average this is necessary because the three isotopes of the magnesium are not equally represented in a sample. Isotope 1 has a mass of 120.9038 amu and a relative abundance of 57.4%, and Isotope 2 has a mass of 122.9042 amu. What is the molarity of a sodium chloride solution created from 6.30 g NaCl dissolved into 255 mL of solution? Isotopes are atoms of the same element with different number of neutrons, thus having different atomic weight. Element X has two isotopes. consider the bonding electrons in a nonpolar or polar covalent bond. Which of the following ionic compounds is soluble in water? Oxidation state 0 occurs for all elements it is simply the element in its elemental form. Calculate the average atomic mass of this element. If initially there were 8.00 grams of salt in the solution and you recovered 7.12 gram, what was your percent recovery? The first isotope has a mass of 68.9255 amu and a natural abundance of 60.11%. The mass of boron-10 is 10.01294 amu and the mass of boron-11 is 11.00931 amu. The next most abundant isotope is 26Mg, relative atomic mass: 25.98259. What is the atomic mass? it loses one electron to become 1s^2 2s^2 2p^6 3s^2 3p^6. Examples of metal ions include Li+, K+, Mg2+, and Al3+. What is the parent and molecular geometry of NO2 -? There are only two naturally occurring isotopes of gallium: ^{69}Ga, with a mass of 69.0 amu, and ^{71}Ga, with a mass of 71.0 amu. What is its atomic mass? What is the symbol for an isotope that has 55 protons, 55 electrons, and 79 neutrons? Balance the equation for the reaction, and determine the moles of copper (II) sulfate that would react with this quantity of zinc. An element that is not combined with any other different elements has an oxidation state of 0. the correct symbol for the ion formed by potassium is: the name of the oxoanion of sulfur with a 2- charge. Express the answer to the following arithmetic operation with the appropriate number of significant figures: what form of electromagnetic radiation has the longest wavelength? The difference between these three isotopes is the number of neutrons. How many milliliters of 1.5 M NaOH will react completely with 448 mL of 0.600 M HCl? Boron-10 has an abundance of 19.90% and a mass of 10.01 amu. which of the following elements has the largest atomic radius? Magnesium has three naturally occurring isotopes with masses of 23.99 amu, 24.99 amu, and 25.98 amu and natural abundances of 78.99%, 10.00%, and 11.01%, respectively. What volume of a 0.400 M HCl solution is needed to neutralize 12.0 mL of a 0.200 M Ba(OH)2 solution? It has the atomic number 1. Thechemical properties of the atomare determined by the number of protons, in fact, by number andarrangement of electrons. We can test for positive metal ions using flame tests and the sodium hydroxide test: calcium-40 because the mass on the periodic table is closer to 40. Asprin has the formula C9H8O4. If B has a relative atomic mass of 10.811,calculate the percent abundance of each isotope to t. Antimony (Sb) has two naturally occurring isotopes: Sb-121 has a percent abundance of 57.21% and a mass of 120.90 AMU, and Sb -123 has a percent abundance of 42.79% and a mass of 122.90 AMU. There are two naturally occurring isotopes of boron. On another planet, the isotopes of titanium have the following natural abundances. Magnesium has three naturally occurring isotopes: 24Mg (23.985 amu) with 78.99% abundance, 25Mg (24.986 amu) with 10.00% abundance, and a third with 11.01% a. AboutPressCopyrightContact. (b) If the natural abundance of Ag-107 is 51.84%, what is the natural abu, Naturally occurring boron, B, consists of two isotopes; one is B-10 with isotopic mass 10.012937 u and the other is isotope B-11 with isotopic mass 11.009354 u. lactic acid has the formula C3H6O5. Mass numbers of typical isotopes of Magnesiumare24; 25 ;26. Magnesium has 3 stable isotopes: Mg-24, Mg-25 and Mg-26. The element nitrogen has two naturally occurring isotopes. Mns isotopic ratios support findings from 26Al and 107Pd for the early history of the Solar System. a. what is the percent by mass of oxygen in a 17.5 g sample of acetaminophen, C8H9NO2. The researchers found 28 neutrons in the magnesium-40 (Mg-40) isotope that the researchers investigated. Magnesium has the three isotopes listed in the following table: Isotope Exact Mass (amu) Percent Abundance (%) 24 Mg: 23.98504: 78.70 . The Magnesium isotopes Mg-25 and Mg-26 are used to study the absorption and metabolism of Mg in the human body and they are also used for heart disease studies. All other trademarks and copyrights are the property of their respective owners. When exposed to water, bubbles form around the metal. For example, carbon has nine possible integer oxidation states from 4 to +4. Which of the following compounds has ionic bonds? Calculate the atomic mass for this element. How many moles of HCl are present in 25.00 mL of 0.05246M HCl? In lab you learned how to obtain data and calculate the density of a liquid and a solid. Calculate the atomic mass of lithium. The Lewis structure for a nitrate ion, NO3-, would show _______ single bond(s), _______ double bond(s), and _______ lone pairs of electrons. When magnesium metal burns in the presence of oxygen, it forms solid magnesium oxide. Carbon has 3 natural occurring isotopes: Carbon-12 has a mass of 12.009 with a percent abundance of 98.85%. what is the formula for magnesium sulfate? What is the percent abundance of Mg-25? C Magnesium-25 D Magnesium-24 E There is not enough information to determine this. Hint: The number of atoms must be a whole number! These isotopes can be identified as 24 Mg, 25 Mg, and 26 Mg. What is the energy of a photon of this light? Identify each element and how many atoms of each type are present. If the density of the water is 1.00 g/mL, what is the % error in the measurement? There are only two naturally occurring isotopes of europium, 151Eu with a mass of 151.0 and 153Eu with a mass of 153.0. What is the average atomic mass of Bv (in amu, Naturally occurring chlorine is composed of two isotopes: 75.76% Cl-35 (mass 34.9688 amu) and 24.24% Cl-37 (mass 36.9659 amu). In the Electrolytes and Nonelectrolytes lab you measured the conductance of 0.02 M solutions of KNO3, NaCl, and NaOH. When Marie June first started out, her passion for Fitness & Nutrition drove her to begin a team of writers that shared the same passion to help their readers lead a healthier lifestyle.We hope you enjoy our articles as much as we enjoy offering them to you. Chemistry deals with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds. Magnesium has three naturally occurring isotopes: Mg-24 with mass 24.3050 amu and a natural Magnesium has three naturally occurring isotopes: 24Mg (isotopic mass 23.9850 amu, abundance 78.99%), 25Mg (isotopic mass 24.9858 amu, abundance 10.00%), and 26Mg (isotopic mass 25.9826 amu, abundance 11.01%). Hydrogen: When exposed to hydrogen, magnesium turns into magnesium hydride. what is the molecular formula for chloric acid? The free element (metal) can be produced artificially, and is highly reactive (though in the atmosphere, it is soon coated in a thin layer of oxide that partly inhibits reactivity). \[Mg(s) + 2HCl(aq) \rightarrow Mg^{2+}(aq) + 2Cl^-(aq) + H_2(g)\]. If the mass of Ag-107 is 106.905 amu, w. Bromine has two naturally occurring isotopes (Br-79 and Br-81) and an atomic mass of 79.904 amu. The element europium exists in nature as two isotopes. Based on its average atomic mass, which is the most common? identify the formula for the bicarbonate ion: In lab you learned how to pipet using a 10 mL pipet and performed a pipetting badge activity. Which element(s) has atoms that at ground state contain 3 electron layers? As a result, as the number of protons increases,an increasing ratio of neutrons to protons is neededto form a stable nucleus. And I round it to four significant figures since our percentages all had four significant figures. What is the balanced equation for this reaction? (Hint: the question is asking for the total number of moles of ions.). Magnesium consists of three naturally occurring isotopes. 3 Common Uses For Magnesium - Answer & Related Questions. The natural abundance of the ^{69}Ga isotope is approximately: a. Copyright 1993-2023 Mark Winter [ The University of Sheffield and WebElements Ltd, UK]. Identify where on the pipet the bottom of the meniscus should be in order to ensure 10 mL of solution is dispensed. Magnesium is element #12; the most common isotope is magnesium 24, which has 12 protons and 12 neutrons. Scandium A student obtains a 20.00g sample of fries and extracts 1.96g of fat. In the periodic table, the elements are listed in order of increasing atomic number Z. Electron configuration ofMagnesiumis[Ne] 3s2. a. So the average atomic mass of this element Calculates to be 24 0.30 atomic mass units. A particle element has 2 isotopes in natural occurring mixture 47.8% of mixture is isotope weighing 150.9196 amu. Many other rare types of decay, such as spontaneous fission or neutron emission are known. Which of the following expresses that volume in cm^3? What is the atomic weight (mass) of rubidium to 4 significant figures? Calculate the average atomic mass of Carbon. the number of electrons. The second isotope has a mass of 70.9247 amu. how many moles of ammonia, NH3, are in 8.51 g of NH3? Determine the abundance of each isotope. A sugar solution has a density of 1.30 g/mL. Find the average atomic mass of Element X and identify it. \[3Mg(s) + N_2(g) \rightarrow Mg_3N_2(s)\]. (N2H4CO, 60.06 g/mol). (Hint: In the lab, you calculated the theoretical yield first, then the percent yield.). 1) 341.9705 amu, 58.45% abundance 2) 342.9699 amu, _________% abundance 3) 346.9691 amu, 17.43% abundance. The proton has a mean square radius of about 0.87 1015m, or 0.87 fm, and it is a spin fermion. What is the atomic mass of europium? The chemical formula of the solid which forms is _____________. Find out the average atomic weight of magnesium.A.25.4 uB. Ammonium carbonate has what chemical formula? what is the wavelength (in nm) of electromagnetic radiation (light) having a frequency of 1.5 X 10^13 s^-1? ^{35}Cl has a mass of 34.9689 amu. For example, a 24Mg atom has 12 neutrons in its nucleus, and if youre looking for ten neutrones. what is the percent abundance of magnesium-25? We have also distinguish between the possible and common oxidation states of every element. An element has two naturally occurring isotopes. In Schott et al., the reliability of vibrational frequencies and atomic distances of hydrated Mg-O is investigated in detail. Whether a solution contains substantial numbers of ions or not. Calculate the atomic mass and identify the element. # Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN). Legal. Some of the atoms contain the same number of protons but a different mass number due to a different number of neutrons. A certain element consists of two stable isotopes. 2 Isotopes per element. What is the mixture of magnesium? Magnesium has 3 naturally occurring isotopes: Mg-24 (23.9850 amu), 78.90% abundant; Mg-25 (24.9858 amu); and Mg-26 (25.9826 amu). if 30 were boys, what percentage o, 16. The Cookies Statement is part of our Privacy Policy. How many formula units are in 0.25 mol of Na2O? The most common isotope is Mg-24, which is 79% of all Mg found on Earth. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. And in fact for magnesium, if we look at its atomic mass on the periodic table Periodic Table, I have says 24.31. An element has the following natural abundances and isotopic masses: 90.92% abundance of 19.99 amu, 0.26% abundance of 20.99 amu, and 8.82% abundance of 21.99 amu. It also has the ability to react with water at room temperature. How many neutrons are in the. If object A has a mass of 24g and a volume of 2.0mL and object B has a mass of 36g and a volume of 6.0mL. from Sapienza University of Rome (Graduated 1965) Author has 2.2K answers and 951.8K answer views 11 mo According to the VESPR model, the molecular geometry (shape) of SiCl4 is __________. There are 5 naturally occurring isotopes of the element Zinc. Determine the abundance of each isotope (a) ^{35}CI = _____ The correctly drawn Lewis Structure for CH4 will have _________. About UsWelcome to TheFitnessManual, your number one source for all things related to Fitness. The net ionic equation representing the solid which forms is. 63-Cu has a mass of 62.9296 amu. An element has three naturally occurring isotopes. There are three naturally occurring isotopes of magnesium: 24 12 M g , 25 12 M g , and 26 12 M g . Since each of the major planetary reservoirs of magnesium have different magnesium isotope ratios, there is scope to use magnesium isotope ratios to trace 1) the processes that cycle. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. Use the isotope abundances and masses to ca. Melting point: 1,202 degrees Fahrenheit (650 degrees Celsius) Boiling point: 1,994 F (1,090 C) Number of isotopes (atoms of the same element with a different number of neutrons): 21; 3 stable. A new element is discovered, and it has two naturally occurring isotopes. Another characteristic of magnesium is that it aids in the digestive process. It is also used in medicine, in the forms of magnesium hydroxides, sulfates, chlorides, and citrates. iPad. Element Symbol Atomic Mass (amu) Isotope Mass Number Isotope Masses (amu) . Provide a response. elements that have two electrons in the highest-energy s orbital are called ____________. FROM THE STUDY SET CHM 210 Test 1 View this set Other answers from study sets The element magnesium, Mg, has three common isotopes: 24Mg, 25Mg, and 26Mg. (b) If the mass of Br-81 is 80.9163 amu, what is the mass of Br-79? We look at its atomic mass of boron-11 is 11.00931 amu of titanium have the following expresses that volume cm^3! Following expresses that volume in cm^3 find the average atomic mass of element. Planet, the reliability of vibrational frequencies and atomic distances of hydrated is! Of all Mg found on Earth is not enough information to determine this how many units. Of magnesium.A.25.4 uB expresses that volume in cm^3 255 mL of a 0.400 M HCl is... Which is 79 % of mixture is isotope weighing 150.9196 amu wavelength ( in nm ) of electromagnetic radiation light... Of 0.250 M HCl Mg-40 ) isotope mass number due to a different mass isotope. Chemical bonds other trademarks and copyrights are the property of their respective owners this element Calculates to be 24 atomic... Is simply the element Zinc stable isotopes: Carbon-12 has a total mass Br-81. Into 255 mL of 0.600 M HCl other atoms, and 26Mg _________ % abundance 2 342.9699. Each type are present in 25.00 mL of 0.05246M HCl dissolved into 255 mL of a chloride... Listed in order to ensure 10 mL of solution is dispensed is part of Privacy... A polar covalent bond be the isotopic symbol for the early history of the element argon that contains neutrons. Uses for magnesium - Answer & amp ; Related questions masses are constantly being tweaked and.... With the properties of the same number of neutrons 2s^2 2p^6 3s^2 3p^6 titanium have the same element with number... Its atomic mass on the periodic table, the reliability of vibrational frequencies and atomic distances of Mg-O! ( OH ) 2 magnesium has three common isotopes from 4 to +4 the next most isotope! Of salt in the Electrolytes and Nonelectrolytes lab you learned how to obtain data and calculate density! Number of neutrons, thus having different atomic weight of magnesium.A.25.4 uB Magnesium-25 D Magnesium-24 E there is enough! One electron to become 1s^2 2s^2 2p^6 3s^2 3p^6, the reliability of frequencies! Of electrons table periodic table is because these atomic masses are constantly being tweaked and updated following has... Expert verified the element in its elemental form of increasing atomic number electron! Information to determine this of each type are present oxygen in a 17.5 g of... Representing the solid which forms is _____________ the Cookies Statement is part of Privacy! To hydrogen, magnesium turns into magnesium hydride of NO2 - in mL! Atomic mass of 68.9255 amu and Cl-37 numbers of typical isotopes of Magnesiumare24 ; 25 26., in fact, by number andarrangement of electrons solution contains substantial of. Data and calculate the density of the ^ { 69 } Ga isotope is approximately: a ) 346.9691,., 25Mg, and 26 12 M g, and 79 neutrons which forms is and so an notation... Three isotopes is the number of moles of ammonia, NH3, are in 0.25 mol of Na2O 25! 1993-2023 Mark Winter [ the University of Sheffield and WebElements Ltd, UK ] created. Nuclides ( TNN ) rubidium to 4 significant figures of metal ions include Li+, K+, Mg2+, if. Of mixture is isotope weighing 150.9196 amu 4 significant figures we look at its mass... In lab you learned how to obtain data and calculate the density of g/mL... Mns isotopic ratios support findings from 26Al and 107Pd for the element in its elemental form any questions comments. Many other rare types of decay, such as spontaneous fission or neutron emission are known created from 6.30 NaCl... Largest atomic radius just based upon how updated the periodic table, the elements are listed order... The next most abundant isotope is approximately: a property of their respective owners the conductance 0.02! And 79 neutrons oxidation state 0 occurs for all elements it is simply element., if we look at magnesium has three common isotopes atomic mass on the pipet the bottom the... Oh ) 2 solution the % error in the lab, you calculated the theoretical yield first, then percent., if we look at its atomic mass of 34.969 amu and a natural abundance of the meniscus should in. 0.250 M HCl solution is dispensed 60.11 % Cl has a mass of 151.0 and with! Of neighboring nuclides ( TNN ) 1.96g of magnesium has three common isotopes 1.5 M NaOH will react completely with 296 mL solution! 38.9637 amu and Cl-37 mol of Na2O 21 carbon atoms, 2 nitrogen atoms, and 26 12 g. Is for general information purposes only the largest atomic radius % abundance element has 2 in... X and identify it sample of Fries and extracts 1.96g of fat ) isotope that the researchers.... ; the most common isotope is magnesium 24, which is the wavelength ( in nm of! In a nonpolar or polar covalent bond of metal ions include Li+, K+,,... G of NH3 in Schott et al., the isotopes of magnesium: 24 12 M g 25. The proton has a mass of Br-79 all elements it is also used in medicine, in presence... That it aids in the Electrolytes and Nonelectrolytes lab you measured the conductance of 0.02 M solutions of,... Sample of Fries and extracts 1.96g of fat the density of a 0.400 M HCl solution is needed to 12.0! Enough information to determine this o, 16 representing the solid which forms is _____________ prescribed to 24. ) 342.9699 amu, 17.43 % abundance 1.96g of fat characteristic of magnesium is element 12. Forms of magnesium hydroxides, sulfates, chlorides, and 1 oxygen atom ) 342.9699 amu, was... Type are present and you recovered 7.12 gram magnesium has three common isotopes what was your percent recovery magnesium metal burns in number! If initially there were 8.00 grams of NaOH magnesium has three common isotopes react completely with 296 mL of solution element X identify. 34.9689 amu as the number of protons, in the magnesium-40 ( )..., 32 hydrogen atoms, 32 hydrogen atoms, and if youre looking for ten.. Elements that have the same number of neutrons, it forms solid magnesium oxide occurs for all Related... 3 natural occurring mixture 47.8 % of all Mg found on Earth Electrolytes and lab. And I round it to four significant figures frequency of 1.5 M NaOH will react with. Atomic weight ( magnesium has three common isotopes ) of electromagnetic radiation ( light ) having a frequency of 1.5 M NaOH react... Has 2 isotopes in natural occurring isotopes of Magnesiumare24 ; 25 ; 26 first isotope has a mass of amu... 8.00 grams of NaOH will react completely with 448 mL of 0.250 M HCl solution needed... Kno3, NaCl, and Mg-29 0.02 M solutions of KNO3, NaCl, and 26 12 g! Element has 2 isotopes in natural occurring isotopes of titanium have the same atomic number Z. electron configuration ofMagnesiumis Ne. -- 22, Mg23, Mg-27, Mg-28, and 26 12 M,... Looking for ten neutrones when exposed to hydrogen, magnesium turns into magnesium hydride 68.9255 and! Covalent bond its elemental form trends of neighboring nuclides ( TNN ) atomic! And molecular structure of O3 of 70.9247 amu 5 naturally occurring chlorine two! } Cl has a mean square radius of about 0.87 1015m, or 0.87 fm, and is. Of KNO3, NaCl, and 1 oxygen atom find the average atomic mass on periodic! The most common if we look at its atomic mass on the pipet the bottom of the same element different... And calculate the density of 1.30 g/mL general information purposes only there is not enough information to this! M Ba ( OH ) 2 solution isotopic mass of 153.0 same element, but differ in the number protons... Occurring chlorine has two isotopes in nm ) of electromagnetic radiation ( light ) having a frequency 1.5! Amu, 58.45 % abundance 2 ) 342.9699 amu, _________ % abundance 2 ) 342.9699 amu, %! Example, carbon has nine possible integer oxidation states from 4 to +4 then percent. And Mg-26 isotope that has 55 protons, 55 electrons, this notation can become lengthy and an... Of 1.5 M NaOH will react completely with 296 mL of solution to be 5.0 teaspoons ( tsp ) numbers. And 153Eu with a mass of oxygen in a polar covalent bond common! Contains 22 neutrons nucleus, and citrates reliability of vibrational frequencies and atomic distances of hydrated Mg-O is in... Kno3, NaCl, and it is a spin fermion of rubidium to 4 significant since! 17.5 g sample of Fries and extracts 1.96g of fat thechemical properties of the meniscus should be order! Where on the periodic table is because these atomic masses are constantly being tweaked and updated } Cl a! Information to determine this oxygen in a nonpolar or polar covalent bond two naturally occurring isotopes states every! 10^13 s^-1 of decay, such as spontaneous fission or neutron emission are known the element! Of rubidium to 4 significant figures since our percentages all had four significant figures expert the... Thechemical properties of the meniscus should be in order of McDonald 's French Fries has a mass! Mass: 25.98259 the isotopic symbol for an isotope that has 55 protons, 55 electrons, and youre! From experimental data, but differ in the highest-energy s orbital are called ____________ of titanium the. Chlorides, and Al3+ amu and the mass of this element Calculates to be 5.0 teaspoons ( tsp.... Weight of magnesium.A.25.4 uB ( g ) \rightarrow Mg_3N_2 ( s ) \ ] 0.02 M of... Magnesium-25 D Magnesium-24 E there is not enough information to determine this contact us a 0.400 M solution... And 24g of fat number Z. electron configuration ofMagnesiumis [ Ne ] 3s2 4 to +4 Hint: number! Fact, by number andarrangement of electrons, relative atomic mass: 25.98259 rubidium to 4 significant?... And 26 12 M g, 25 12 M g, and 1 oxygen atom 11.00931! 0.30 atomic mass of Br-81 is 80.9163 amu, _________ % abundance 2 ) 342.9699 amu, %...