1. τ = λ
2. τ = 1/λ
3. τ = λ/ln(2)
4. τ = ln(2)/λ

1. 0, 1, 2, 3
2. 0, 1, 2
3. 1, 2, 3
4. -1, 0, +1

1. 2n + l
2. 2n + 2l
3. 2(2l + 1)
4. 2l + 1

# If a nucleus with Z = 80 emits the particles in the following sequence:

1. α, β, β, α, α, α, α, α, β, β, β+, α, β+
2. What is the value of Z of the resulting nucleus
1. 56
2. 66
3. 78
4. 82

# The radius of the first orbit of the electron in the hydrogen atom is 0.53 A0. Then the radius of the second orbit is:

1. 2.12 A0
2. 4.24 A0
3. 0.193 A0
4. None of the above

1. hf/c
2. hc/f
3. hc/λ
4. λ/hc

1. +e
2. -e
3. +2e
4. -2e

# Nuclear forces are stronger than:

1. Gravitational forces
2. Electrostatics forces
3. Magnetic forces
4. All of the above forces

1. Alpha rays
2. Beta rays
3. Gamma rays
4. X-rays

# Nuclei having the same number of neutrons are called:

1. Isotopes
2. Isobars
3. Isotones
4. Isodiapheres

# The angular momentum of electrons in an atom produces:

1. Spin waves
2. Magnetic moment
3. Light
4. All of above