ASTR 1101 : ASTR Test 3
Document Summary
If the sun burned like coal or wood, it would only last 10,000 years: gravitational energy, compressed material gets hot, but the sun can only be 107 yr old, nuclear reactions, fusion, combining atoms together, ex. H + h + h + h = he: fission, breaking an atom apart, ex. 238u -> 206pb: each decay process has a specific half-life, half-life of 238u is 4. 47 billion years, that means that in 4. 47 billion years, half of the 238u that we had in the beginning will, ex. Beginning: 10 years, 20 years, 30 years, 40 years, 50 years have decayed into 206pb. Y = 96. 875: as long as we can assume there was no y to begin with, then the amount of y tells us how much. Z has decayed: thus, z + y tells us the value of z0, comparing z0 to z gives us how long z has been decaying. Impacts on earth: basically like sand blasting, mt.
