An atom of helium has a radius of 31. pm and the average orbital speed of the electrons in it is about 4.4x 10 m/s calculate the least possible uncertainty in a measurement of the speed of an electron in an atom of helium. write your answer as a percentage of the average speed, and round it to 2 significant digits x 10

The question is incomplete, here is the complete question:

An atom of helium has a radius of 31. pm and the average orbital speed of the electrons in it is about . Calculate the least possible uncertainty in a measurement of the speed of an electron in an atom of helium. Write your answer as a percentage of the average speed, and round it to 2 significant digits

The percentage of average speed is 41 %

Explanation:

We are given:

Radius of helium atom = 31 pm =    (Conversion factor:   )

So, diameter of helium atom =

The diameter of the atom will be equal to the uncertainty in position.

The equation representing Heisenberg's uncertainty principle follows:

where,

= uncertainty in position = d =

= uncertainty in momentum  =

m = mass of electron =

h = Planck's constant =

Putting values in above equation, we get:

To calculate the percentage of average speed, we use the equation:

We are given:

Average orbital speed =

Putting values in above equation, we get:

Hence, the percentage of average speed is 41 %

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

i would say b

explanation:

but i think i would need more information than that