Help asap Part
Light can bounce off objects. This is called reflection, and it's what allows us to see objects.
Although many light waves are hitting the paper and reflecting from it, showing just one ray helps
us follow the path of a single wave.
Hector shows the class a picture that models what happens as the students observe the blue
construction paper when the flashlight is shining on it.
white
light
blue light
blue construction paper
For each color of paper, which part of white light is reflected?

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

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