# Worksheet: The Bohr Model of the Atom

In this worksheet, we will practice calculating the orbital radius of an electron in different energy levels of a hydrogen atom.

**Q1: **

If an electron had a charge that was twice its actual charge but the proton still had the same charge, according to the Bohr model of the atom, by what factor would the Bohr radius change?

- A2
- B
- C4
- D
- E1

**Q2: **

If an electron in a hydrogen atom is at a distance of 1.32 nm from the nucleus, what energy level is it in? Use a value of m for the Bohr radius.

**Q3: **

If the proton had a mass 1.5 times its actual value, according to the Bohr model of the atom, by what factor would the Bohr radius change?

**Q4: **

Use the formula ,
where is the orbital radius of an electron in energy level of a hydrogen atom,
is the permittivity of free space,
is the reduced Planck constant, is the mass of the electron, and is the charge of the electron,
to calculate the orbital radius of an electron that is in energy level of a hydrogen atom. Use a value of
Fā
m^{ā1}
for the permittivity of free space, Jā
s for the reduced Planck constant,
kg for the rest mass of an electron,
and C for the charge of an electron.
Give your answer to 3 significant figures.

**Q5: **

An electron in a hydrogen atom has an angular momentum of Jā s. Under the Bohr model of the atom, what energy level is the electron in? Use a value of Jā s for the reduced Planck constant.

- A3
- B4
- C6
- D1
- E2

**Q6: **

In the Bohr model of the atom, what is the magnitude of the angular momentum of an electron in a hydrogen atom in the ground state? Use a value of Jā s for the reduced Planck constant.

- A Jā s
- B Jā s
- C Jā s
- D Jā s
- E Jā s

**Q7: **

The Bohr radius is a physical constant that is equal to the distance between the nucleus and
the electron of a hydrogen atom in the ground state.
Its value is given by the formula .
Calculate the value of the Bohr radius. Use a value of Fā
m^{ā1}
for the permittivity of free space,
Jā
s for the reduced Planck constant,
kg for the rest mass of an electron,
and C for the charge of an electron. Give your answer to 3 significant figures.

- A m
- B m
- C m
- D m
- E m

**Q8: **

If the electron had a mass that was twice its actual mass, according to the Bohr model of the atom, by what factor would the Bohr radius change?

- A
- B1
- C4
- D
- E2

**Q9: **

Use the formula , where is the orbital radius of an electron in energy level of a hydrogen atom, is the permittivity of free space, is the reduced Planck constant, is the mass of the electron, and is the charge of the electron, to calculate the orbital radius of an electron that is in energy level of a hydrogen atom. Use a value of F/m for the permittivity of free space, Jā s for the reduced Planck constant, kg for the rest mass of an electron, and C for the charge of an electron. Give your answer to 3 significant figures.

**Q10: **

If both the electron and the proton had charges that were twice the size of their actual charges, according to the Bohr model of the atom, by what factor would the Bohr radius change?

- A1
- B4
- C
- D
- E2