Flashcards on Nuclear Decay

Define Activity (A)

The rate of decay of a sample of radioactive nuclei, measured in Becquerel (Bq), equivalent to s⁻¹.

Define Decay Constant (λ)

A constant that represents the probability of decay of a nucleus per unit time, measured in s⁻¹.

Define Number of Nuclei (N)

The total count of radioactive nuclei present in a sample.

Define Time (t)

The duration over which decay is measured, expressed in seconds (s).

Define Half-life (T½)

The time required for the number of radioactive nuclei or the activity to reduce to half of its initial value.

Define Alpha Radiation (α)

A type of nuclear decay where a nucleus releases fast-moving helium nuclei, resulting in a smaller, more stable nucleus.

Define Beta Radiation (β)

A type of nuclear decay where a neutron decays into a proton and releases a fast-moving electron.

Define Gamma Radiation (γ)

A type of nuclear decay where an unstable nucleus releases energy in the form of a gamma photon, often accompanying alpha or beta decay.

What are Penetrating Properties

The ability of different types of radiation (alpha, beta, gamma) to penetrate materials,

Order Penetrating power of radiation, from most to least

Gamma

Beta

Alpha

Define Background Radiation

The radiation present in the environment that must be accounted for when measuring radioactivity, often subtracted from experimental data.

Define Exponential Decay

The process by which the quantity of radioactive nuclei decreases over time, represented graphically as an exponential curve.

What is the equation for Activity?

A = λN,

A is the activity,

λ is the decay constant,

N is the number of nuclei.

Equation for Remaining Nuclei

N = N₀ e⁻λt,

N₀ is the initial number of nuclei,

λ is the decay constant,

t is time.

Equation for Activity Over Time

A = A₀ e⁻λt,

A₀ is the initial activity,

λ is the decay constant,

t is time.

Logarithmic Form of Half-life

When t = T½,

the relationship can be expressed using natural logarithm as N/N₀

Define Nuclear Decay

The breaking down of atom.

Nucleus emitting or intaking something to make it more stable.

What are the 4 different types of nuclear force?

1. Strong

2. Weak

3. Electromagnetic

4. Gravitational

What 2 words describe the nature of Nuclear Decay?

Random and Spontaneous

Order, gamma, alpha, and beta starting with the most ionising

• Alpha

• beta

• Gamma

Define Becquerel

a unit of radioactivity of a given sample of material equal to one atomic decay per second

What is the value of converting years to seconds?

3.15 x 10⁷