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1. we start with 400 atoms of uranium-238. how many remain after 4.5 billion years? after 9 billion years? after 13.5 billion years?

2 . how long will it take for ½ of the original amount of rubidium-87 to decay?

3. carbon-14 has a half-life of 5,730 years. how does that compare to those listed in the chart?

what possible advantages or disadvantages would this give c-14 when used for radiometric dating?

The many volcanoes located along the edge of the pacific ocean make up the ring of fire. how does subduction play a role in the volcanic activity in the ring of fire?

The endoplasmic reticulum (er) is an organelle in some cells. in these cells, it is continuous with the nuclear membrane and forms a large part of the cell\'s total membrane. sort the phrases below as describing rough er, smooth er, both, or neither. note: if you answer any part of this question incorrectly, a single red x will appear indicating that one or more of the phrases are sorted incorrectly.1) found in prokaryites and uekaryotys2) involved in protein synthesis3) involve in lipid synthesis4) contains molecular chaperones in lumen5) bound with ribosomes6) involved in toxin or drug metabolism7) large systemot internnected tubules, vesicles, and sacs8) "packages" enzymes in vesicles for secretion.

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. chinchilla x albino a) all chinchilla b) 1/2 chinchilla, 1/2 albino c) 3/4 chinchilla, 1/4 albino