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Atoms & Molecules

Physics Problems

How does the number of atoms in a 26.5 gram gold ring compare to the number in a silver ring of the same mass? Amoung the higest and lowest temperatures recorded are 136degrees F in the Libyan desert and -129Degrees F in the Antarctica. What are these in Celsius? To make a secrue fit, rivets that are larger than the rivit

How many Coulombs of charge are on the electrons in a nickel coin?

We want to find how many Coulombs of charge are on the electrons in a nickel coin. Follow this method. a) A nickel coin has a mass of about 5.172 g. Each mole (6.02 * 10^23 atoms) has a mass of about 57.98 g. Find the number of atoms in nickel coin. b) Find the number of electrons in the coin. Each nickel atom has 28 elect

Solving: Kinetic Theory of Gases

Hi, I need some assistance with the following problems: 1. If the translational rms speed of the water vapor molecules (H2O) in air is 664 m/s, what is the translational rms speed of the carbon dioxide molecules (CO2) in the same air? Both gases are at the same temperature. 2. Near the surface of Venus, the rms speed of c


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

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?

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

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?


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

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.

Ultrasoound waves/ Degassed water

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

Practice question to get accustomed to significant numbers.

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.