Lesson 13: Nuclear Chemistry Flashcards
Nuclear Chemistry
The study of reactions that involve changes in nuclear structure.
Radiation
Energy given off by matter in the form of rays or high speed particles.
Four Types of Radiation
- Alpha particle(a).
- Beta particle(B).
- Gamma radiation(Y).
- Positron(B+).
Element Symbol
Letter that is the symbol of the element.
Atomic Number
Number of protons in the nucleus of and atom. (Different for each element).
Mass Number
Sum of the number of protons and neutrons in an atom. (Whole number).
Atomic Mass
Average number of neutrons and protons for all natural isotopes of and element. (Decimal number)
Nuclide
Atom with a particular number of protons and neutrons.
Isotopes
Atoms (nuclides) with same number of protons but a different number of neutrons.
Nuclear Force
Strong force that holds the protons of the nucleus together. (Neutrons major component of this force).
Unstable Nuclei (Radioactive Elements)
Have either to much protons or too many neutrons upsetting strong nuclear forces.
Radioactive Decay
Unstable nuclei (radioactive elements) trying to balance themselves by giving up excess protons or neutrons.
Radionuclide
Nuclide that has excess number of either protons or neutrons giving it excess energy and making it unstable.
Alpha Particle (a) - (Description/composed of) 4,2He
Same components as a helium nucleus. (4 Mass Number - 2 Atomic Number)
Lowest penetrating power of the four types of radiation (piece of paper will shield it).
Alpha Particle 4,2He
Beta Particle (B) (Def) 0,-1B or 0,-1e
High speed electron that is ejected from the nucleus.
100 times more penetrating power than the alpha particle. (Piece of aluminum foil will block or shield it)
Beta particle 0,-1B or 0,-1e
Gamma Radiation (Y) (a stream of what) 0,0Y
A stream of high-speed photons.
Penetrating power 10,000 greater than the alpha particle. (Lead reinforced concrete is required to shield it).
Gamma radiation 0,0Y
Positron (B+) - Description (o,+1B or 0,+1e)
Particles with the same mass as an electron but w/ 1+ positive charge.
Penetrating Power
The ability of each type of radiation to pass through matter.
Ionizing Power
The ability of radiation to damage molecules.
Nuclear Stability Trends
- Nuclides w/ 84 or more protons are unstable.
- Even numbers of protons and neutrons are often more stable than odd numbers. (2n and 2z) more stable than (7n and 4z).
- Stable nuclides want to have a neutron proton ratio (n/z) equal to one for lighter elements (z <= 20). For heavier elements stable nuclides want to have a n/z ratio greater than one.
- Magic numbers of protons and/or neutrons produce stable nuclides. (2,8,20,28,50,82,126)
Balancing Nuclear Equations (Two Rules)
- The sum of the Mass Numbers of the reactants equals the sum of mass numbers of the products.
- The sum of the charges (Atomic Numbers) of the reactants equals the sum of the charges (Atomic Numbers) of the product.
Antimatter
Particles with the same mass but the opposite sate of another property (for example, charge).
-Positrons and Electrons
Radioactive Decay
Spontaneous change of an unstable nuclide into another.
Parent Nuclide
The unstable nuclide in radioactive decay. (Nuclide before disintegration).
Daughter Nuclide
Nuclide that results from the decay (may be stable or unstable).
Radiation
Energy given off by matter in the form of rays or high-speed particles.
Alpha Decay (Def) (Emission of what from nucleus)
Emission of a high-speed particle from the nucleus —-> 4,2He or —–> 4,2 a
Beta Decay (Def) (Emission of what from nucleus)
Emission of an electron from a nucleus
—> 0,-1B or 0,-1e
Positron Emission (Emission of what from nucleus).
Emission of a positron from the nucleus.
—-> 0,1B or —-> 0,1e
Electron Capture (what combines with what and is converted into what) and what is released.
An inner shell electron combines with a proton and is converted into a neutron.
x-ray is released
0,-1e —–>
Gamma Decay (what is released and how does it decay)
Gamma radiation is released.
(Decays from an excited state to a lower (ground) state).
—–> 0,0Y
4,2a or 4,2He (a)
Alpha particle (a)
0,-1B or 0,-1e (B)
Beta particle (B)
0,1B or 0,1e (B+)
Positron (B+)
0,0Y (y)
Gamma radiation (Y)
Predicting Route of Nuclear Decay (Alpha Decay)
Heavy elements (A > 200) (z > 83)
Atomic mass greater than 200 and atomic number greater than 83.
Predicting Route of Nuclear Decay (Beta Decay)
Too many neutrons and not enough protons.
n:z ratio too high
Predicting Route of Nuclear Decay (Positron Emission and Electron Capture)
Too many protons and not enough neutrons
n:z ratio too low
Conversion of Neutron into proton (what type of decay)
Beta Decay
Conversion of a proton into neutron (what type)
Positron emission
Change in mass(A)/atomic numbers(z) - from Parent to Daughter: Alpha Decay
A: decrease by 4
Z: decrease by 2
Change in mass(A)/atomic numbers(z) - from Parent to Daughter: Beta Decay
A: unchanged
Z: increase by 1
Change in mass(A)/atomic numbers(z) - from Parent to Daughter: Gamma Decay
A: unchanged
Z: unchanged
Change in mass(A)/atomic numbers(z) - from Parent to Daughter: Positron Emission
A: unchanged
Z: decrease by 1
Change in mass(A)/atomic numbers(z) - from Parent to Daughter: Electron Capture
A: unchanged
Z: decrease by 1
Radioactive Series
The changes a radioisotope undergoes as it decays
