Earth quiz 2 Flashcards
(22 cards)
what’s an isotope
atom with different number of nuetrons than normal
absolute or radiometric dating is…
dating using radiometric decay
absolute or radiometric dating is…
dating using radiometric decay
relative dating is…
placing events based on a sequence
absolute or radiometric dating is…
dating using radiometric decay
absolute/ radiometric dating gives you…
an exact number/date
relative dating gives you…
a sequence of evemts
what is half-life…
the time it takes for half of the parent to decay
why does atomic number decrease by one for electron capture
a proton takes in a nearby electron to form nuetron so the number of protons is decreased which results in atomic number going down by 1
an alpha emission is…
when 2 protons and 2 neutrons are released from nucleus so atomic number goes down by 2 and atomic mass goes down by 4
beta emission is when…
a nuetron in nucleus is split into proton and electron so electron is shot out while atomic number increases by 1
what kind of nucleus is released during alpha emission
a helium nucleus is released bc 2 protons and 2 nuetrons
why doesn’t atomic mass change in beta emission
protons and neutrons weigh the same so when it splits, the weight stays the same since electrons have no mass either.
what are steno’s laws
law of superposition, law of crosscutting, fossil/ fauna succession, law of inclusions
what is law of inclusions
any rock fragment found in another rock is older than the rock it’s found in
what’s the law of superposition
rocks on top are the youngest and rocks on bottom are oldest (undisturbed sequence)
the concept of original horizontal is that
all layers of rock lay flat
the idea of lateral continuity is
everything extends out in all directions
law of cross cutting is
any feature that cuts through layers of rocks in younger than the rocks it cuts through
the order of fossil/fauna succession is…
fossils on the top are younger than fossils at the bottom
if you have the same fossils…
then those layers were set down at the same time
strata is…
a layer of rock in the ground
