The Bohr Model of the hydrogen atom proposed that there were very specific energy states that the electron could be in. These states were called stationary orbits or stationary states. Higher energy states were further from the nucleus. These orbits were thought to be essentially spherical shells in which the electrons orbited at a fixed radius or distance from the nucleus. The smallest orbit is represented by n=1, the next smallest n-2, and so on, where n is a positive integer representing the shell or orbit. What is the radius of the n 5 orbit for Hydrogen (2 1)? Submit Answer Incorrect. Tries 2/10 Previous Tries Each shell has a very specific energy. Note that the energy of zero is used to represent the level at which an electron becomes unbound from the nucleus and can fly free. The energies for the Bohr orbits are all negative, which means they are all shells in which the electron is bound in orbit around the nucleus. What is the energy for the n-2 Bohr orbit for Hydrogen (Z-1) expressed in Joules? (do not enter units) Submit Answer Tries o/10 what is the energy for the n=2 Bohr orbit for Hydrogen (Z=1) expressed in eV? (do not enter units) Submit Answer Tries 0/1O job of calculating the energy levels for lons that are hydrogen-like, meaning they may have more protons in the nucleus, but they only have one electron. Examples would be He The Bohr Model does a good LI+2, Bet3 What is the radius of the n-5 Bohr orbit for B4 (Boron, Z-5)? Submit Answer Tries 0/10 What is the energy of the n-2 Bohr orbit for Be+3 (Beryllium, Z-4)? You can use your choice of energy units. Make sure to enter units this time Submit Answr Tries 0/10 Solution part a: bohr radius of nth orbit for hydrogen is given by r=4*pi*epsilon*(h/(2*pi))^2*n^2/(m*e^2) where epsilon=electrical permitivity=8.85*10^(-12) h=planck’s constant=6.626*10^(-34) m=mass of electron=9.1*10^(-31) kg e=magnitude of charge on electron=1.6*10^(-19) C r=5.3090*10^(-11)*n^2 for n=5, radius =1.3272 nm part b: energy is given by -13.6/n^2 eV for n=2, energy=-3.4 eV =-5.44*10^(-19) J part c: energy in eV=-3.4 eV part d: radius for hydrogen like ions=a0*n^2/Z where a0=5.3090*10^(-11) m for Boron ion, Z=5 hence for n=5,radius=0.26545 nm part e: energy for hydrogen like ion=-13.6*Z^2/n^2 using Z=4 and n=2 energy value=-13.6*4^2/2^2=-54.4 eV .

1. The Bohr Model of the hydrogen atom proposed that there were very specific energy states that
the electron could be in. These states were called stationary orbits or stationary states. Higher
energy states were further from the nucleus. These orbits were thought to be essentially spherical
shells in which the electrons orbited at a fixed radius or distance from the nucleus. The smallest
orbit is represented by n=1, the next smallest n-2, and so on, where n is a positive integer
representing the shell or orbit. What is the radius of the n 5 orbit for Hydrogen (2 1)? Submit
Answer Incorrect. Tries 2/10 Previous Tries Each shell has a very specific energy. Note that the
energy of zero is used to represent the level at which an electron becomes unbound from the
nucleus and can fly free. The energies for the Bohr orbits are all negative, which means they are
all shells in which the electron is bound in orbit around the nucleus. What is the energy for the n-
2 Bohr orbit for Hydrogen (Z-1) expressed in Joules? (do not enter units) Submit Answer Tries
o/10 what is the energy for the n=2 Bohr orbit for Hydrogen (Z=1) expressed in eV? (do not
enter units) Submit Answer Tries 0/1O job of calculating the energy levels for lons that are
hydrogen-like, meaning they may have more protons in the nucleus, but they only have one
electron. Examples would be He The Bohr Model does a good LI+2, Bet3 What is the radius of
the n-5 Bohr orbit for B4 (Boron, Z-5)? Submit Answer Tries 0/10 What is the energy of the n-2
Bohr orbit for Be+3 (Beryllium, Z-4)? You can use your choice of energy units. Make sure to
enter units this time Submit Answr Tries 0/10
Solution
part a:
bohr radius of nth orbit for hydrogen is given by
r=4*pi*epsilon*(h/(2*pi))^2*n^2/(m*e^2)
where epsilon=electrical permitivity=8.85*10^(-12)
h=planck’s constant=6.626*10^(-34)
m=mass of electron=9.1*10^(-31) kg
e=magnitude of charge on electron=1.6*10^(-19) C
r=5.3090*10^(-11)*n^2

2. for n=5, radius =1.3272 nm
part b:
energy is given by -13.6/n^2 eV
for n=2, energy=-3.4 eV
=-5.44*10^(-19) J
part c:
energy in eV=-3.4 eV
part d:
radius for hydrogen like ions=a0*n^2/Z
where a0=5.3090*10^(-11) m
for Boron ion, Z=5
hence for n=5,radius=0.26545 nm
part e:
energy for hydrogen like ion=-13.6*Z^2/n^2
using Z=4 and n=2
energy value=-13.6*4^2/2^2=-54.4 eV