An unknown element X has the following isotopes: ¹⁴⁰X (89.00% abundant) and ¹⁴²X(11.00% abundant). What is the average atomic mass in amu of X?

Q: How many atoms are present in 1.5 moles of nickel?

A:

Q: Explain clearly what is meant by the statement “The atomic mass of gold is 197.0 amu.”

A: “The atomic mass of gold is 197.0 amu.” The explanation of the above statement has to be given…

Q: A sample of monochloro pentaborane (9), B5H8Cl, has a mass of 20.7 g. What amount, in moles, does…

A: Chemical formula of monochloro pentaborane = B5H8Cl.Above compound contains B, H and Cl atom.

Q: Naturally occurring copper consists of 63Cu (mass 62.9296 amu) and 65Cu (mass 64.9278 amu), with an…

A:

Q: The water found on Earth is almost entirely made up of the 'H and 1°0 isotopes for a formula of H20…

A: The different variants of a particular element, that are differed by the number of neutrons. In…

Q: In what mass units are the average atomic mass and molecular mass expressed? What is the value of…

A: The average atomic mass and molecular mass is expressed in atomic mass unit (amu). It is defined as…

Q: X is an element with 3 isotopes, X-139, X-140 and X-141. The relative abundance of each isotope is…

A: If A1 , A2 and A3 are mass numbers of three isotopes of an element with relative abundance X1 , X2…

Q: How many atoms of carbon are combined with 7.70 moles of hydrogen atoms in a sample of the compound…

A: C2H6 From this Molecule we get that ; 1 mol C2H6 contain ; 2 mol Carbon and 6 mol Hydrogen    We can…

Q: An unknown element X has the following isotopes: ¹⁰X (20.00% abundant) and ¹¹X (80.00% abundant).…

A: The term isotopes can be defined as the variants of a given chemical element that differ in neutron…

Q: The density of helium in a balloon is 1.18 g/L. If a balloon holds 2.91 L of He, how many atoms of…

A: Calculation of mass of Helium: Mass=Volume×density=2.91 L×1.18 g/L=3.4338 g Calculation of no. of…

Q: The density of helium in a balloon is 1.18 g/L. If a balloon holds 2.95 L of He, how many atoms of…

A: It is given that :Density of helium in a balloon = 1.18 g/LVolume = 2.95 L

Q: The atomic mass of aluminum is 26.982u. How many alluminum atoms are in a 4.55g sample of aluminum?

A: Mass of aluminium sample=4.55 g The atomic mass of aluminum =26.982 u Moles of aluminium=4.5526.982…

Q: Which of the following has more atoms: 3.55 g ef lithium atoms or 19.1 g of nickel atoms?

A: Mass of lithium = 3.58 g Mass of nickel = 19.1 g

Q: An unknown element X has the following isotopes: 140X (89.00% abundant) and 142X(11.00% abundant).…

A: Since,         Average Atomic mass=Σass of Isotope×% of Isotope100

Q: Assume the atomic mass of element X is 22.99 amu. A 22.42−g sample of X combines with 123.73 g of…

A: Mass of X = 22.42 g Mass of Y =123.73 g Atomic mass of element X = 22.99 amu Atomic mass of element…

Q: The density of helium in a balloon is 1.18 g/L. If a balloon holds 2.93 L of He, how many atoms of…

A: The mass of the species can be defined as the product of the density of the species and the volume…

Q: There are 6.02x1023 atoms in one mole of any element. Assuming that the titanium rod in the question…

A: Given that, Number of moles of titanium = 4.70 moles

Q: What is the mass of 4.06 moles of sodium atoms?

A:

Q: The density of helium in a balloon is 1.18 g/L. If a balloon holds 2.99 L of He, how many atoms of…

A:

Q: Diamond is one form of an elemental carbon. An engagement ring contains a diamond weighing 1.25…

A: Given, Diamond is one form of an elemental carbon and an engagementring contains a diamond weighing…

Q: How many moles of Kr are there in a sample of Kr that contains 2.74×1024 atoms?

A: The relationship between the moles and number of atoms of any element is given by  moles = number of…

Q: A sample of cyanic acid, HCN, contains  3.33 x 1022 atoms. a. How many moles of cyanic acid are in…

A:

Q: 3.123 In the formation of carbon monoxide, CO, it is foundthat 2.445 g of carbon combine with 3.257…

A:

Q: An unknown element X has the following isotopes: 126X (22.00% abundant), 128X (34.00% abundant),…

A: These are three isotopes of element X are given .Calculate the average atomic mass of X in…

Q: An unknown element X has the following isotopes: 25X (80.5% abundant) and 27X (19.5% abundant). What…

A: Given, The natural abundance of isotope I, 25X = 80.5 % The natural abundance of isotope II, 27X =…

Q: What is the mass of a mole of electrons if one electronhas a mass of 9.11 × 1 0 -28 g?

A: Because, 1 mole=6.022×1023 molecules/particles Therefore, 1 mole of electron=6.022×1023 electrons

Q: According to the law of multiple proportions, if 12 g of carbon combine with 16 g of oxygen to form…

A: According to the law of multiple proportion, two atoms combining in different ratios to form…

Q: How many grams of sugar C12H22O11 that consists of 1.25 x 1024 atoms of hydrogens?

A: Given that ; We have to determine the mass of sugar (in g) that consists of 1.25 x 1024 atoms of…

Q: A toy top has a mass of 32.0Cu. How many atoms Сu are in this spinning top, given that the average…

A: One mole of any substance consists of 6.022×1023 particles.Number of moles of any substance present…

Q: any atoms of cesium are in 10.1 grams ium phosphate? 1

A: Cesium phosphate Cs3PO4 molar mass = 494 g/mol Moles of Cs3PO4=mass/molar mass    = 10.1/494 =…

Q: A toy top has a mass of 32.0g Cu. How many atoms Cu are in the spinning top, given that the average…

A: Given information: Mass of Cu = 32.0 g Molar mass of Cu = 63.55 g/mol

Q: Calculate the mass of each sample. a. 1.05 × 10²26 atoms of neon, Ne(g)

A: 1 mole of atom = 6.022 × 1023 atoms

Q: 23 atoms of magnesium? 1. How many moles of magnesium is 5.61 x 10

A: moles of any species is defined as when given mass of species divided by its molar mass

Q: How many grams of Zn are there in a sample of Zn that contains 4.33x1023 atoms? grams

A: Using molar mass of Zn, grams of Zn present in a sample of Zn can be calculated.

Q: Natural rubidium has the average mass of 85.4678 u and is composed of isotopes85Rb (mass = 84.9117…

A: Mass of the Rb = 86.913 amu. Given data: 85.4678 amu is average mass of the Rb Mass of 85Rb =…

Q: Question attached

A: Atomic mass: It defined as the mass of the atom that is present in an element expressed in terms of…

Q: Aluminum bronze is a mixture of 92.0% copper (Cu) and 8.0% aluminum (Al) by mass. What percent of…

A: Given : Mass percent of Al = 8.0 % And mass percent of Cu = 92.0 % Assuming 100 g of mixture. Hence…

Q: An unknown element X has the following isotopes: 5X (72.5% abundant) and 67X. What is the average…

A:

Q: How many atoms of Pt are present in 2.53 moles of Pt?

A:

Q: An unknown element X has the following isotopes: $2X (84.50% abundant), 49X (8.00% abundant), 5°X…

A: Given element has three isotopes Isotope - 1 : 52X Mass number (A1) = 52 Percentage abundance (X1) =…

Q: What is the average mass of the atoms ? (Copper-63 has a mass of 62.92960 amuamu, and copper-65 has…

A: The average atomic mass of the element is defined as the sum of the mass of all the isotopes present…

Q: An element, X. forms a compound with Carbon for which the formula is XC₂. If 37.48% of the compound…

A: An element, X. forms a compound with Carbon for which the formula is XC₂. If 37.48% of the compound…

Q: An unknown element X has the following isotopes: ⁵⁸X (68.00% abundant), ⁶⁰X (26.00% abundant), ⁶²X…

A:

Q: 2. How many moles would there be in 500 atoms of Silver? - 3. What is the mass of exactly 230 Sodium…

A:

Q: Natural rubidium has the average mass of 85.4678 u and is composed of isotopes85 Rb (mass = 84.9117…

A: Mass of the Rb = 86.913 amu. Given data: 85.4678 amu is average mass of the Rb Mass of 85Rb =…

Q: How many lithium atoms are present in 49.17 moles of lithium?

A: 1 mole contains 6.022 ×1023 atoms

Q: An unknown element X has the following isotope: 25X (80.5% abundant) and 27X (19.5% abundant). What…

A: Given : Isotope 1 : X25            Atomic Mass = 25           % Abundance = 80.5 %…

Q: xplain how the atomic mass unit (amu) is defined and (ii) explain how the definition of an amu in…

A: A Unit of mass is used to explain the atomic weight....i. e amu. Atomic mass is the quantity of…

Q: An element X has two common isotopes: X-57 and X-59. If the average atomic mass of element X is…

A: An element has two isotopes : X-57 and X-59 Average Atomic mass = 58.876 amu

Mole Concept

Mole concept is a method to determine the amount of any substance that consists of some elemental particles using a grouping unit called ‘mole’. The mole concept enables one to handle the large amount of small elementary particles. The mole concept can be used in many calculations related to mole calculation, molar amount, mole ratio, and so on, which are significant in chemistry.