Nuclear Chemistry Flashcards
The difference in the larger mass of the constituent protons and neutrons than that of the original nucleus
Mass defect
An amount of energy required to break up a given nucleus into it’s constituent protons and neutrons. This is also the energy that holds the nucleons together in the nucleus.
Binding energy
Atomic number describes ?
Number of protons
Mass number describes ?
Number of protons and neutrons
The number of ____ determines the identity of an element. The number of ____ determine different isotopes of the same element
Protons
Neutrons
Another name for radio active isotope
Radio nucleotide
Nuclear reactions :
What are changed ?
Reaction energy ?
Reaction rates?
What is invoked ?
Elements or isotopes are changed from one to another
Larger amounts of energy is released or absorbed
Rates not affected by catalysts temperature or pressure
Protons neutrons and electrons can be involved
Chemical reactions :
What is changed ?
Reaction energy
Reaction rates
What is involved ?
Atoms are rearranged through breaking or forming chemical bonds
Release or absorption of small amounts of energy
Rates affected by catalysts temperature or pressure
Only electrons in the affected orbital are involved in breaking or forming bonds
What is the most stable atom / has the highest binding energy per nucleon
Iron
Atomic mass of a proton ?
Atomic mass of a neutron ?
- 00728 amu
1. 00867 amu
How many protons and neutrons are in a helium atom ?
2 protons , 2 neutrons
Process in which a large heavy (mass number > 200) atom splits to form smaller, more stable nuclei and one or more neutrons.
Fission
Is energy absorbed or released in fission ?
A large amount is released
When a certain nuclei absorbs a low energy neutron and fission is induced in certain nuclei. When they release more neutrons in turn this is called
Chain reaction
What is the only radio active decay that causes a change in the mass number ?
Alpha decay. -4 to mass number
This is similar to an electron but has a positive charge. What is it ? When are they emitted ?
Positron (beta +)
Occurs when a proton or neutron in the nucleus decays
Beta - means that ?
Beta + means that ?
Neutron is consumed , a proton takes it’s place
Proton is consumed , a neutron takes it’s place
Therefore mass number doesn’t change. Only atomic.
The only radioactive decay that the atomic number increases ?
Beta -
What is more penetrating ? Alpha or beta decay ?
Beta because of the slight charge on them
Emission of high energy photons and allows the nucleus to shed excess energy
Gamma decay
Certain unstable radio nucleotides are capable of capturing an inner ___ that combines with a proton to form a neutron. What happens to the atomic mass ?
Electron
Decreases by 1
