Answer to Question 1
Radioactive emissions are the direct products of fission; they are generally unstable isotopes of their respective elements. The unstable isotopes become stable by ejecting subatomic particles (alpha particles, beta particles, and neutrons), or high-energy radiation (gamma rays), or both.
Exposure to radiation increases the risk of cancer. Low doses of radiation may damage DNA. Some people argue that there are doses of radiation below which there would be no adverse effect because of the DNA repair mechanisms that exist. Others argue that no safe level of exposure exists. High doses of radiation can block cell division, resulting in death.
Answer to Question 2
Interspecific competition is competition between species, while intraspecific competition is competition within a species. Interspecific competition occurs when ecological niches overlap. Intraspecific competition occurs because members of the same species are competing for the same resources. Intraspecific and interspecific competition are forms of environmental resistance that limit a population size because these types of competition result from density-dependent biotic and abiotic factors that are necessary for survival.
Because of the hazards of a vacuum, astronauts must wear a pressurized space suit while outside thei
Spiral Produced by twisting stresses that are spread along the length of a bone (note the break in t
Plate movements and the geological hazards
Major Agricultural Crops Produced in the United States, 2011
Types of Radioactive Decay
For the circuit in Figure 1, assume ideal diodes. The peak inverse voltage is approximately