Achieve#19

[asheagg3I]

Hi, Can someone help me with Achieve #19? I'm not sure what the dot above the A represents. Do you just use the Heisenberg Interdeterminacy Equation? Also, how do parts a and b of the question differ from one another?

[Quade Albert 2J]

the dot above the a represents the unit angstrom which is 10^-10 meter. Yes, the heisenberg interdeterminancy equation is used here. the first question involves an electron which has a different mass than the atom in question b.

[Anthony Stone 1K]

The A with the dot above it represents angstrom. The conversion factor for this is on the equation sheet. Yes, you just use the heisenberg equation where you solve for delta P. Delta P then equals m(mass) * delta V. Solve for delta v. They differ from one another because in part a you are using the mass of an electron but in part b you are using the mass of helium which you have to convert from g/mol to kg. 1kg = 1000g. 1mol = 6.022x10^23 atoms. kg/atom is what you want.

[Myra Goraya Dis 2E]

The dots above A represent the unit angstrom, one angstrom is equal to 1*10^-10 meter. Both part a and part b are the same with different uncertainties of position. You will use Heisenbergs equation but you must convert 11 angstrom and 1 angstrom to meters before plugging them in to the equation. For part A you would use the mass of the electron as well which is 9.11*10^-31 kg in order to computer velocity and for part B you would take one molecule of helium and convert it to moles using avogrados number then find the mass using molar mass then converting it into kg. After determining the meters of uncertainty of position and the mass for part of the momentum, you will end up only not knowing what velocity is. With that, you can solve for velocity.

[KyLee 1H]

Hello, the A with the dot symbolizes an angstrom, which is 10^-10 m. Use it to find delta x. Then, use the uncertainty equation for the rest. Remember though, that it is asking for delta v not delta p, so make sure to convert between the two with the help of mass.

[Shania Garrison Discussion 3E]

Hi. The dot of above the A means that it is the symbol for the unit "Angstrom" which is equal to 10^-10 m. This is not an SI unit but used by chemists when discussing wavelengths and distances between atoms.

[Nithya Narapa Reddy]

It means that the units are in angstroms which is equal to 1x10^-10m and is usually used when doing calculations for interatomic distances.

[Zoe Dhalla 3I]

Hi!

Basically, to go about this problem, you would have to find the minimum uncertainty in an electron's velocity by rearranging the uncertainty equation to solve for Δv.

Δv ≥ h/(4pi x m x Δx)

Planck's constant is 6.626×10–34 J·s and the mass of an electron is 9.109×10–28 g or 9.109×10–31 kg. Convert the uncertainty in the electron's position from angstroms to meters, 11 Å=1.1×10−9 m. The minimum uncertainty in velocity is when Δv is equal to this expression.

To find the minimum uncertainty in a helium atom's velocity, first find the mass of one helium atom from the molar mass.

Then, convert the uncertainty in the helium atom's position from angstroms to meters, 1.4 Å=1.4×10−10 m. The minimum uncertainty in velocity is when Δv is equal to this expression.


Hope this helps!