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    Atoms & Molecules

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    Molecules

    What kinds of evidence supports the belief that molecules of various kinds, including some complex ones, exist in space? Please include references to support answer.

    Calculating force, power, equilibrium, and energy

    1. A Ping-Pong ball has a diameter of 3.8 cm and average density of 0.084 g/cm3. What force is required to hold it completely submerged under water? 2. A tank with a cover, containing a liquid of density p, has a hole in its side at the distance y1 from the bottom. The diameter of the hole is small relatively to the diamete

    Number of molecules

    An expandable chamber contains 16.0 kg of molecular oxygen at STP. How many molecules are in it? How many moles?

    Atomic Mass Hydrogens

    Question: What is the mass of hydrogen and the mass of oxygen in one liter of water? How many atoms of hydrogen and atoms of oxygen does it contain? What is the mass of one H2O molecule in kilograms?

    Vibrating Hydrogen Molecule

    When displaced from equilibrium by a small amount, the two hydrogen atoms in an H_2 molecule are acted on by a restoring force F_x = k_1*x with k_1 = 650 N/m. Calculate the oscillation frequency f of the H_2 molecule. Use m_eff = m/2 as the "effective mass" of the system, where m in the mass of a hydrogen atom. Take the mass of

    Interstellar space: pressure, rms speed of the atoms

    Interstellar space, far from any stars, is filled with a very low density of hydrogen atoms (H, not H_2). The number density is about 1 atom/cm^3 and the temperature is about 3K. A & B) Estimate the pressure in interstellar space. Give your answer in Pa and in atm. C) What is the rms speed of the atoms? D) What is the e

    The Speed of Nitrogen Molecules

    The Speed of Nitrogen Molecules The kinetic theory of gases states that the kinetic energy of a gas is directly proportional to the temperature of the gas. A relationship between the microscopic properties of the gas molecules and the macroscopic properties of the gas can be derived using the following assumptions: • The ga

    Water condensation

    Please do not place your response in a .pdf or .cdx format, but Word documents are okay. Thanks! Here's the actual problem: 3x10^4 cm^3 of 400 degrees Celsius steam at a pressure of 20.0 atm is cooled until is condenses. What is the volume of the liquid water? Give your answer in cm^3.

    Multiple Choice Questions

    1. Nitrogen may be combined with oxygen in proportion by mass of 1.75 g nitrogen to 1.00 g oxygen to form the gas nitrous oxide, N2O. The same elements may be combined in the ratio of 0.438g nitrogen to 1.00g oxygen. What is the atomic composition of the second compound? a. NO(2) b. NO c. N(2)O d. NO(3) 2. I

    Molecular Mass, the Mole, and Avagadro's Number

    Question: The artificial sweetener NutraSweet is a chemical called aspartame (C14 H18 N2 O5). A) What is its molecular mass (in atomic units)? B)What is the mass (in kg) of an aspartame molecule?

    Microstates of Polymer Links

    1) Polymers, like rubber, are made of very long molecules, usually tangled up. Another very crude model of a rubber band is that each link is either crumbled up or stretched. If it is crumbled up, its length is negligible and it is in the lowest energy state, call it E = 0. If it is stretched, then its length is L and it is in

    Thermal Physics and Gas Molecules

    In a 10 m^3 room at standard temperature and pressure, what is the probability of finding all of the gas molecules, in the left most 99% of the room?

    Continuous Probability Distribution - Escape Velocities of Hydrogen Molecules

    The surface of the sun has a temperature of about 5800K and consists largely of hydrogen atoms. We're given that the rms speed of a hydrogen atom at this temperature is 1.20*10^4m/s and the escape speed for a particle is 6.20*10^5m/s. Can appreciable quantities of hydrogen escape from the sun? Can any hydrogen escape?

    Body water question

    Assume that the human body is 75% water. How many moles of water are in your body? How many molecules? If I am 75% water, then why am I always getting thirsty? My body weight is 165lbs.

    Water degassing techniques - description

    When doing ultrasound work and the sound waves must pass through water, it is important to used gegassed (outgassed) water. This can be done by one of several methods. One is to make the pressure above the water sample as low as possible, i.e., a partial vacuum. The other is to boil the water at normal pressures. Discuss the phy

    Ranking pressures in order of increasing temperature.

    You have six sealed containers, all having the same volume, that contain ideal gases with a different number of molecules at various pressures. The values of the number of molecules (N) and the pressure (P) are listed below. Rank these containers in order of increasing temperature, from smallest to largest. (If B is lowest, th

    Calculating the center of mass of a molecule

    The carbon monoxide molecule (CO) consists of a carbon atom and an oxygen atom separated by a distance of 1.13 * 10^-10 m. The mass of mc = 0.750 mo. Determine the location of the center of mass of this molecule relative to the carbon atom.

    Interaction between two atoms

    A commonly used potential energy function to describe the interaction between two atoms is the Lennard-Jones potential U=e((Ro/R)^12-2(Ro/R)^6) a) Show that the radius at the potential minimum is Ro, and that the depth of the potential well is e. b) Find the frequency of small oscillations about equilibrium for 2 identi

    Estimate the total number of electrons in any molecule

    If you remove all the electrons from a rain drop (diameter = 1 mm), what would be the gain in the electrostatic potential of the entire earth? Consider the radius of the earth to be R=6378.14 km. The answer clearly in by the simplest way illustrates the solution.

    Precision and Significant Figure Calculations

    The answer should not contain more significant figure than the question. A carbon dioxide molecule contains a carbon atom and two oxygen atoms. Calculate its mass in: a) atomic mass units b)kilograms. (Amu of carbon = 14, Amu of oxygen = 16) See attachment below.