Obtain an estimate for the number of atoms in the universe. Make the following assumptions: (a) All of the atoms in the universe are hydrogen atoms in stars. (This is not a ridiculous assumption because over threefourths of the atoms in the universe are in fact hydrogen. Gas and dust between the stars represent only about 15% of the visible matter of our galaxy, and planets compose a far smaller fraction.) (b) The sun is a typical star composed of pure hydrogen with a density of 1.4 g/cm^3 and a radius of 7x10^8 m. (c) Each of the roughly 100 billion stars in the Milky Way galaxy contains the same number of atoms as our sun. (d) Each of the 10 billion galaxies in the visible universe contains the same number of atoms as our Milky Way galaxy.

Q: The lanthanide elements react with oxygen to give compounds of the type Ln2O3 (where Ln stands for a…

A: Empirical formula :- The simplest formula which shows only the relative number of atoms of different…

Q: Give the number of atoms of the specified element in a formula unit of each of the following…

A: a) The given compound is C6H5COONH4 The number of a hydrogen atom is 9 The molecular mass of the…

Q: v, the number of v of Rf is 104 and its v is 267. Therefore the number of protons is One of the…

A:

Q: the number of copper atoms in a 3.0g lump of copper is 2.8x1022 .how many electrons present in the…

A: Number of copper atoms = 2.8 × 1022  We need to determine number of electrons present.

Q: A certain metal, M, forms two oxides, M2O and MO. If the percent by mass of M in M2O is 73.4%, what…

A: The answer is given below

Q: 2. A sample of a substance containing only carbon, hydrogen, and oxygen has mass x in grams. It is…

A: The equation for the burning of carbohydrate is: x12a+b+16c CaHbOc  +  O2   →    y44CO2  +  Z18…

Q: 3. In a chemical atomic mass determination, the tin content of 3.7692 g of SnCl, was found to be…

A: We’ll answer the first question since the exact one wasn’t specified. Please submit a new question…

Q: Give the number of atoms of the specified element in a formula unit of each of the following…

A: Given: (a) Oxygen in aluminum sulfate, Al2(SO4)3(b) Hydrogen in ammonium hydrogen phosphate,…

Q: If the same amount of electricity that is used to produce 500 g copper metal (Cu Cu") is used to…

A: Given: Mass of Cu produced = 500 g. The moles of Cu produced = MassAtomic mass = 50063.55 = 7.868…

Q: How many grams of CH3CO2C5H11 must be weighed out to provide 3.22 x 1023 atoms of H? When you input…

A: Mole in terms of particles : 1 mol = 6.022 x1023 particles  where particles =…

Q: One mole (molecular equivalent) of gold has a mass of 196.9655 g.  One mole of anything equals 6.022…

A: Given : Mass of gold (1 mole)= 196.9655 g  Diameter of gold = 3.58 × 10-10 m Block of gold of mass =…

Q: The density of solid Cr is 7.15 g/cm3. How many atoms are present per cubic centemeter of Cr?

A: Mass = Volume x density Number of moles = Mass/molar mass Number of molecules = 6.0224 x 1023 x…

Q: Iron exists in nature as a mixture of predominantly three isotopes: 26Fe (53.94 amu), 56 neFe (55.93…

A:

Q: On a periodic chart of the elements, molar mass (M), also called atomic weight, is often listed as…

A: A chemical compound consists of two or more different elements which are bonded with each other…

Q: Explain the difference between the terms molecularmass and formula mass. To what type of…

A: The difference between molecular mass and formula mass has to be explained and the type of compound…

Q: Imagine you mix 16.05 g of methane (CH4) gas and 96.00 g ofoxygen (O2) gas and then ignite the…

A: First order reaction is a reaction that proceeds at a rate that depends linearly on only one…

Q: What is the mass, in g, of one molecule of ethane, C2H6?

A: One mole of substance has Avogadro number of atoms. 1 mole of substance=6.022×1023 molecules. Number…

Q: Caffeine, a stimulant found in coffee, contains 49.5%% CC, 5.15%% HH, 28.9%% NN, and 16.5%% OO by…

A: Mass percentage of constituent elements of caffeine in the molal mass of 195 g/mol are: 49.5% by…

Q: Calculate the number of atoms of silicon (Si) in 415 cm3of the colorless gas disilane at 0°C and…

A: GIVEN: Density of disilane =  0.00278 g cm-3 Volume of disilane = V=415 cm3   The molecular formula…

Q: What percentage of the mass of a phosphorus 32 atom is contributed by its electrons, given the mass…

A: Phosphorus-32 has 15 electrons. Mass of electrons in Phosphorus-32 can be calculated as follows,…

Q: Polyisobutylene is a synthetic elastomer, or rubber. The corresponding monomer is isobutylene, which…

A: Given, molecular formula C4H8

Q: 2. In a chemical atomic mass determination, the tin content of 3.7692 g of SnCl4 was found to be…

A: In SnCl4 one Sn atom combine with 4 chlorine atom. Given mass of SnCl4 is 3.7692 g and mass of Sn is…

Q: In the ammonia (NH) molecule of the figure, the three hydrogen (H) atoms form an equilateral…

A: You can find the center of mass of the 3 Hs first, then find the center of mass between that point…

Q: Matter is neither created nor destroyed in a chemical reaction. Thus, the mass of the products of a…

A:

Q: With the advent of techniques such as scanning tunneling microscopy, it is now possible to “write”…

A: Given:Surface is 20 atoms high and 14 atoms wide.Number of Platinum atoms = 20 atoms × 14 atoms =…

Q: In using a mass spectrometer, a chemist sees a peak at a mass of 30.0106 AMU. Of the choices 12C2…

A:

Q: What is the molar mass of the compound with the formula X2Y2Z7, where X is an alkali metal from the…

A: Given: The compound with the molecular formula, X2Y2Z7, X= alkali metal from the 3rd period. Y= an…

Q: Calculate the molecular mass of the following substances: (a) Ibuprofen, C13H18O2 (a drug used as…

A: Introduction: Molar mass is the mass of 1 mole of a substance in a gram. It is also called molecular…

Q: Calculate the mass (in mg) of 9.85 x 1019 CCl2F2 molecules.

A: The relation between mass and number of moles of a substance is as follows,…

Q: Calculate the mass, in grams, of 402 atoms of lithium, Li

A: Number of moles = number of atoms/6.022 x 1023 atoms  Mass = moles x molar mass

Q: Give the number of atoms of the specified element in aformula unit of each of the following…

A:

Q: (a) In the certain hydrated salt MSO3⋅4H2O, the mass percentage of H2O is 44.71%. Identify the…

A: Hydrated Salt -  It is a crystalline salt to which water molecules are loosely bound.  Molar mass of…

Q: 7. What is the mass in grams, of Vitamin C (C6H8O6) that contains 1.076 grams of carbon?

A: Given mass of Carbon = 1.076 g Molar mass of Carbon = 12.01 g/mol Molar mass of C6H8O6 = 176.12…

Q: *(ii) The reaction of ethene with aqueous potassium manganate(VI), KMNO, produces ethane-1,2-diol,…

A: Mass spectrum is used for the separation of ions and fragmentation of ions takes place in the…

Q: Which of the following samples of matter would have the largest mass (grams)? Highlight the letter…

A: 1 mole = 6.02* 1023 molecules  At STP 1 mole of gas = 22.4 Lt  Mass = n . Molar mass where n = no.…

Q: 4. . Which is NOT TRUE about the Law of Conservation of mass? O The number of atoms before and after…

A:

Q: An alcohol is 58.80 % C and 9.889 % H by mass. The rest is oxygen. What is the empirical formula of…

A: We can find the empirical formula of the alcohol using the given percentages of the element. Since…

Q: A block of gold (Au) has the dimensions (I × b x h) = 0.7600 in x 8.558 mm x 1.816 cm. 1 in = 2.54…

A:

Q: What is the molecular weight of sugar, C6H12O6 in atomic mass units? And If you had one mole of…

A:

Q: How many of the indicated atoms are represented by eachchemical formula: (a) carbon atoms in…

A: The number of indicated atoms present in each chemical formula are:

Q: Hydrogen peroxide (H2O2) is a mild antiseptic used to prevent infection in minor cuts and scrapes.…

A:

Q: The molecular formula of hexakis(methylthio)benzene is C12H18S6. What is the percentage (by mass) of…

A: We have to calculate the % by mass of C in hexakis(methylthio)benzene .

Q: Calculate the mass of antimony(III) lodide, Sblg, that can be produced by the reaction of 143 g of…

A:

Q: The molecule Al(OH), has Al atom(s), O atom(s) and v H atom(s). Therefor, the molar mass of Al(OH),…

A: Molar mass is the mass of a chemical element divided by the amount of substance (mol). It can be…

Q: Given that you had 1 mol glucose (C 6H 12O 6), what would the mole ratio of glucose to oxygen be?

A: Balance Chemical equation means number of atoms or ions should be equal in both side (reactant and…

Q: Boron, atomic number 5, occurs naturally as two isotopes, 10B and 11B, with natural abundances of…

A: Isotopes are elements with the same number of protons but differ in the number of neutrons. The…

Q: Boron trifluoride is used as a catalyst in the synthesis of or-ganic compounds. When this compound…

A: When the compound involves boron-11 and fluorine-19 isotope, the molecular mass of the compound is;…

Q: The characteristic odor of decaying flesh is due to the presence of various compounds. One such…

A: Given data contains, Mass percent of carbon is 62.04%. Mass percent of hydrogen is 10.41%. Mass…

Q: 9. Explain how the atomic mass unit (amu) is defined and explain how the definition of an amu, in…

A: amu i.e atomic mass unit is the unit used to express mass .  Avogadro's number = 6.0221 × 1023

Q: An antacid tablet weighing 0.928 g contained calcium carbonate as the active ingredient, in addition…

A: Since you have posted multiple un-related questions, we are entitled to answer the first only.

Stoichiometry

Stoichiometry is a chemical division that evaluates the quantitative content of the chemical process with the help of the reacting molecules or products taking part in the reaction. The term “stoicheion” in “Stoichiometry”, is an old Greek term for "element" whereas “metron” means "measure".