Lesson: Nuclear Decay and Equation

Nuclear Decay and Equation

by Lan Vu

Isotope Recap

• Isotopes are elements with the same number of protons and different numbers of neutrons

• Different numbers of neutrons means different mass

• Mass number = Protons + Neutrons

• Isotopes are named for their different mass number

  • Ex. Carbon-12 has a mass of 12 and Carbon-13 has a mass of 13

​What holds the protons in the nucleus?

​Strong Nuclear Force

• ​"glue" that holds the protons in the nucleus

• ​provided by the the neutrons

Unstable Nuclei = Radiation

• Unstable because the strong nuclear force is not enough to hold the nucleus together

• Atoms with more than 84 protons are unstable

• Radioactivity is the emission of particles/energy from the nucleus

• The nucleus is too big

• This gradually makes more stable isotopes

Multiple Select

Which of these atoms is most likely to undergo some form of radiation? (you can choose more than 1)

• Uranium

• Platinum

• Plutonium

• Cesium

• Hafnium

Alpha

• Alpha decay releases 2 protons and 2 neutrons from the unstable nuclei

• This forms a new atom with an atomic number 2 fewer than the original

• The mass number also decreases by 4

• Alpha radiation is the least harmful

Beta

• Unstable nuclei result in a neutron splitting into an electron and a proton

• The proton stays in the nucleus

• The electron (Beta Particle) gets ejected

• This makes a new atom with an atomic number 1 greater than the original

• The mass stays the same

Gamma

• Unstable nuclei results in the release of high energy radiation

• Gamma rays are pure energy (no mass, no charge) & travels at the speed of light!

• It is usually released with alpha or beta particles

• The nucleus remains the same following this release

• 
  

Nuclear Equations

​Key:

• ​mass number of both side of the arrow must equal

• ​atomic number on both side of the arrow must equal

Multiple Choice

finish the equation

¹⁸¹₇₃Ta --> ____ + ¹⁸¹₇₄W

• ⁴₂He

• ⁰_-1e

• y

Multiple Choice

finish the equation

²²⁶₈₈Ra --> ____ + ²²⁶₈₈Ra

• ⁴₂He

• ⁰_-1e

• y

Multiple Choice

Identify the type of nuclear decay shown here

²¹⁴₈₃Bi → ⁰_-1e + ²¹⁴₈₄Po

• alpha

• beta

• gamma

Multiple Choice

Solve this equation.

₈₅²⁰⁹At = ___ + ₂⁴He

• ₈₃²⁰⁵Bi

• ₈₆²⁰⁹Rn

• ₈₁²⁰⁷Tl

• ₈₅²⁰⁸At

Multiple Choice

Finish this equation

²⁰⁹₈₃Bi--> _{_______ +} ²⁰⁵₈₁Tl

• ⁴₂He

• ⁰_-1e

• y

Multiple Choice

What type of nuclear decay is shown here

¹³⁷₅₆Ba →→ ¹³⁷₅₆Ba + γ rays

• alpha

• beta

• gamma

Multiple Choice

What type of decay is shown here

²³⁸₉₂U ---> ²³⁴₉₀Th + ⁴₂He.

• alpha

• beta

• gamma

Multiple Choice

Solve this equation for.

₆¹⁴C = ___ + _-1⁰e

• ₄¹⁰Be

• ₇¹⁴N

• ₂¹⁰He

• ₆¹³C

Multiple Choice

Solve this equation.

₈₈²²⁶Ra = ___ + ₂⁴He

• ₈₆²²²Rn

• ₈₉²²⁶Ac

• ₈₄²²⁴Po

• ₈₈²²⁵Ra

Multiple Choice

If we start off with element ⁵⁰₂₄X after an gamma decay we get an element(product) that looks like...

• ⁵¹₂₄X

• ⁵⁰₂₃X

• ⁵⁰₂₄X

• ⁵⁰₂₅X