Contriubtors
Atoms
Types of Radiation
Nuclear Stability
Calculations
100
Philosopher that first stated atoms are indestructible and indivisible.
Who is Democritus?
100
The atomic number tells us this.
What are the number of protons in the nucleus?
100
The equation for the alpha decay of thorium-237.
What is 237/90 Th ------> 4/2 He + 233/88 Ra
100
The band of stability represents this
What is a region of a graph representing stable nuclei when the number of neutrons vs. protons for these elements are plotted?
100
Define half life.
What is the amount of time needed for half of an unstable isotope to decay?
200
The Father of the Modern Atomic Theory.
Who is John Dalton?
200
The mass number tells us this
What are the number of protons plus neutrons in an element?
200
Complete the equation and identify as fusion or fission. ? + 1/0 n ----> 92/39 Y + 140/53 I + 2 1/0 n
What is fission? 233/92 U
200
Elements undergo radioactive decay because
Their nucleus is unstable due the ratio of neutrons to protons.
200
You have an isotope with a half-life of 200 years. How much of the original material is left after 600 years?
What is 12.5%
300
Discovered the neutron.
Who is Chadwick?
300
The number of protons neutrons and electrons in 107/47 Ag
What are 47 protons, 47 electrons, and 60 neutrons?
300
The product of the decay represented by this equation 55/25 Mn + 4/2 He -------> ? + 59/27 Co
What is gamma?
300
The range of the neutron to proton ratios for stable elements is
What is 1:1 for elements 1 -20 up to 1.5:1 for elements nearer to atomic number 82? (all elements above 82 are unstable.)
300
Carbon 14 has a half-life of 5,730 years. If an original sample was 100 microgram of C14 and it is now 0.78 microgram of C14, how old is your sample?
What is 40,123 years?
400
The model of the atom proposed by J.J. Thomson.
What is the plum pudding model where negatively charged electrons are distributed throughout a uniform positive charge?
400
Isotopes are
What atoms of the same element with different numbers of neutrons?
400
The equation for position emission by thorium-234
What is 234/90 Th -------> 234/89 Ac + 0/1 e
400
Elements above the band of stability have too many of this subatomic particle and will undergo this type of decay.
What is neutrons, beta decay?
400
The two isotopes of of a particular element have atomic masses and relative abundance of 78.92 amu (50.69%) and 80.92 amu (49.31%). Calculate the atomic mass of this element.
What is 79.91 amu?
500
The significance of the contribution of Rutherford on the model of the atom.
What is gold foil experiment where alpha particles were defected greatly by repulsion from the positive charge in the nucleus? Shows central area for positive charge and location of most of the mass of an atom.
500
The atomic mass for each element is not a whole number because
What is because they are weighted averages of the masses of all the isotopes of that element?
500
The five types of decay and their respective symbols.
What are alpha, beta, gamma, position emission, and electron capture? 4/2 He, 0/-1 e, 0/0 y, 0/1 e, 0/-1 e
500
Elements below the band of stability have too many of this subatomic particle and will undergo this type of decay.
What is protons, positron emission or electron capture?
500
Four modern uses of radioactive decay.
What are PET scans, radiotracers, nuclear energy, radiocarbon dating, food irradiation?
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