Explain why the atomic mass listed on the periodic table is 126.9 amu for an atom of iodine and, for example, not 131 amu or 133 amu.  How is 126.9 amu determined?   Would you ever find one atom of iodine with a mass of 126.9 amu?

Q: etermine the number of atoms in 37.0 grams of sodium, Na. (The mass of one mole of sodium is 22.99…

A: Mass of sodium =37.0g Atomic mass of sodium = 22.99g/mol Moles of sodium = 37.0g/22.99g/mol = 1.61…

Q: 2. Silver has an average atomic mass of 107.87 amu and has 2 isotopes. *Ag has a mass of 106.95 amu…

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Q: On earth, tin has 10 different stable isotopes. The heaviest, 124Sn makes up 5.80% of naturally…

A: Grams of 124Sn present in 38.3 g sample     = 38.3*(5.80/100)= 2.22 g

Q: There are two naturally occurring isotopes of chlorine. 35 Cl has a mass of 34.9689 u. 37 Cl has a…

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Q: A 10.5710.57 g sample of NaBr contains 22.3422.34% Na by mass. Considering the law of constant…

A: According to law of constant composition, the mass percent of any element in any compound always…

Q: The atomic masses of 203Tl and 205Tl are 202.972320 and 204.974401 amu, respectively. Calculate the…

A: Let the isotope of Tl203 be x. Let the isotope of Tl205 be (1-x). Set up the equation.…

Q: Potassium has 2 stable isotopes, 39K and 41K with atomic mass of 38.9637 amu and 40.9618 amu. If the…

A: Given: The average mass of potassium = 39.10 u The atomic mass of 39K = 38.9637 u The atomic mass…

Q: 2. Bromine has two naturally occurring isotopes (Br-79 and Br-81) If the natural abundance of Br-79…

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Q: Calculate the relative abudance of the two europium isotopes.

A: According to the question Eu-151 has mass 150.916 amu and Eu-153 has mass 152.9209.  The average…

Q: How many carbon atoms are there in a diamond (pure carbon) with a mass of 52 mg?

A: The number of carbon atoms can be calculated as follows,

Q: A compound is composed of phosphorus and hydrogen. The mass ratio is 10.2 g of phosphorus to 1.00 g…

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Q: You are given 1.0g samples of Iron, Silicon, and Lithium. Which of the three samples will contain…

A: Given: 1 g sample of Iron, silicon and lithium To find: Sample containing largest number of atoms…

Q: How many grams does 1.44 x 1028 carbon atoms weigh?

A: To calculate the mass in grams for the atoms  First we have to convert the number of Atoms into…

Q: Bromine has two naturally occurring isotopes (Br-79 and Br-81) If the natural abundance of Br-79 is…

A: Given: There are two naturally occurring isotopes of Br. The abundance of isotope 1 = 50.69 % Mass…

Q: Thallium (Tl) has two naturally occurring isotopes: Tl-203 (29.52 % ; mass = 202.972 amu ), and…

A: Average Atomic Mass of an atom can be calculated by using following formula -   Average atomic mass=…

Q: Cesium has 39 known isotopes ranging from mass 112 to 151. If a sample of cesium containing only…

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Q: Copper, which has an average atomic mass of 63.546 amu, has two stable isotopes: copper-63 and…

A: Given,Atomic mass of Copper-63 = 63.546 amuAbundance of Copper-63= 69.15%

Q: Is it possible for 2 Carbon atoms to have different mass numbers? How?

A: Yes, it is possible for 2 Carbon atoms to have different mass numbers.

Q: Weighted average calculation. enter your answer to 2 decimal points. If Chlorine had only two stable…

A: Average atomic mass of Chlorine using natural abundance of its isotopes can be calculated as…

Q: Copper has two naturally occurring isotopes, 63 Cu(62.9396amu)and 65 Cu(64.9278amu). If copper has…

A: %abundance of cu63= |63.546-64.9278|÷|64.9278-62.9396| So solve it  and  27% Cu63 Same for CU65= 73%…

Q: An unknown element X has the following isotopes: ²⁵X (80.50% abundant, mass = 25.03 amu) and ²⁷X…

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Q: Determine the number of atoms in 25.0 grams of sodium, Na. (The mass of one mole of sodium is 22.99…

A: Given, the mass of one mole of sodium is 22.99 gwe are asked to calculate the number of atoms in…

Q: A made up element ey has three natural isotopes. The isotopes each have an atomic mass of 33.02…

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Q: Bromine has an average atomic mass of 79.904 amu. If Br-79 has a mass of 78.92 amu and Br-81 has a…

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Q: Using the average atomic mass of magnesium, calculate the mass (in amu) of 4 magnesium atoms. amu…

A: Atomic mass of magnesium= 24.305 amu  Atomic mass of iodine= 126.90447 amu  1 mole = 6.022 x 1023…

Q: Natural gallium, which has an atomic weight of 69.7230 amu, consists of gallium-69 and gallium-71…

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Q: Consider two compounds. Compound A contains 2.77 g of phosphorus and 9.53 g of chlorine. Compound B…

A: Given,Mass of Phosphorus in compound B =11.9gMass of chlorine in compound B =40.9g

Q: 19,9924 AMU is the mass of one of the three isotopes of neon equaling 90.4838%. One of the other two…

A: Here, the three isotopes of Neon is

Q: There are only two naturally occurring isotopes of Copper, 63 Cu and 65 Cu. Copper has an atomic…

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Q: Naturally occurring bromine is composed of two isotopes: 50.69 % Br-79 (mass of 78.9183 amu) and…

A: Given,Naturally occurring bromine is composed of two isotopes:50.69 % Br-79 (mass of 78.9183 amu)…

Q: If a fictitious element, X, has 2 naturally occurring isotopes; X-44 and X-46.  The atomic mass of…

A: Given: Fictitious element, X, has 2 naturally occurring isotopes; X-44 and X-46.  The atomic mass of…

Q: A 12.0912.09 g sample of NaBr contains 22.3422.34 % Na by mass. Considering the law of constant…

A: According to the law of constant composition, the ratio of the mass of elements in a compound…

Q: A fictitious element X has two isotopes with the following masses and % abundances. What is the…

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Q: A hypothetical element exists as two isotopes: I = 92.00 amu and II = 98.00 amu. If the atomic mass…

A: Suppose fraction of isotope I = A Fraction of isotope II = (1 - A) Atomic mass = A x atomic mass of…

Q: Part B A certain element X has four isotopes. 4.350% of X has a mass of 49.94605 amu. 83.79% of X…

A: We have to calculate no. of neutrons in part A and average atomic mass in part B

Q: A sample of water, H20, has a mass of 38.0 g. How many atoms of oxygen are in the sample? (oxygen…

A: Given,the mass of water ( H2O ) = 38.0 gatomic mass of H = 1.00 g/mol , O = 16.0 g/molAvogadros…

Q: A completely made up element called Krystogen has two naturally occurring isotopes. The atomic…

A: Every atom in periodic table has some atomic mass and atomic number. When atomic number of two…

Q: A 7.83 gram sample of a compound made of hydrogen, carbon, and nitrogen is found to contain 0.290 g…

A: In this problem, I used the concepts of stoichiometry and mass percent composition in chemistry.…

Q: Element X has two naturally occurring isotopes, 20X with a mass of 19.99 amu and 22X with a mass of…

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Q: determine the number of carbon atoms in a one-carat diamond.

A:

Atoms and Molecules

An atom is the smallest unit of an element that possesses all the properties of that particular element. Molecules are the smallest unit of a substance that possess all the properties of that particular substance.