Question 1
What does the term "critical mass" mean? It is the
◦ difference between mass of individual protons and neutrons and the mass of the nucleus.
◦ amount of fissionable material which will self-sustain a nuclear chain reaction.
◦ energy which holds the nucleus together.
◦ mass of fuel in a nuclear reactor core.
Question 2
In fusion reactions to make superheavy elements, energy is required to bring the two nuclei together and to form additional mass. How much energy must be converted into mass for the alpha bombardment of
253Es to form
257Md? (The isotopic masses are
253Es = 253.08294 amu,
4He = 4.00260 amu,
257Md = 257.09558 amu.)
◦ 9.04 × 10
8 kJ/mol
◦ 3.01 × 10
6 kJ/mol
◦ 7.21 × 10
11 kJ/mol
◦ 3.59 × 10
11 kJ/mol
Energy pathways
Elements of Experimental Design.
energy of interaction and distance of particle
The Elements of Cognition
Metabolic Reactions
Atoms and Elements