Radioactive Flashcards
What is the reactant in radioactive decay called?
The parent isotope
What is the product in radioactive decay called?
The daughter isotope
What is given off during radioactive decay?
Radiation
Radiation is given off during what process?
Radioactive decay
What happens to the parent isotope during radioactive decay?
Parent isotope decreases exponentially
the intersection of a radioactive decay graph marks the
Half life (represented as the x-value. Pay close attention to scale).
Half life
The time required for a quantity to reduce to half of its initial value.
The half life of an isotope of an element is
constant.
Different isotopes of the same elements have different
half lives
The daughter isotope is more ___ than the parent isotope
stable
Absolute dating
Calculates an age in years for geologic materials by measuring the presence of a radioactive element. Can give rocks an actual (exact) date or date range in number of years.
Lots of rocks contain ______ minerals that can be used to date the rock.
radioactive
Why are some atoms radioactive?
The nucleus is unstable because there are too many nuetrons. It can no longer hold configuration, so it releases some nuetrons to become stable.
First step to absolute dating
Add the grams of recent sample to determine original grams of the parent isotope in rock when formed.
Second step to absolute dating
Half the starting amount until you reach the number in the same (determine how many half lives have passed)
Third step to absolute dating
Multiply the number of half lives that have passed by the half life time
What kind of rock does absolute dating work best on?
Igneous rocks. gneous rocks are formed when magma cools. Because its cooling rock forms at the same time, all crystals are the same age.
Why is sedimentary rock hard to absolute date?
Deposition and cementation of material within bodies of water and at the surface of the earth (sediments) could be coming from different places, and could be different ages. You would end up dating the individual grains of sediment comprising the rock, not the rock as a whole. These grains could have radically different ages.
Why is metamorphic rock hard to date?
Metamorphic is deep beneath the Earth’s surface, subjected to high temperatures and the great pressure of the rock layers above it = chemistry of rock changes, and the pressure that the rocks are under can occur over long intervals. Thus, different crystal grains can yield different ages. Overall hard)
