Radioactive Dating
Dating
Dating techniques are procedures used by scientists to determine the age of a specimen.
2 types of Dating:
*Relative Dating
*Absolute Dating
Relative Dating -methods tell only if one sample is older or younger than another sample.
-They do not provide an age in years.
Stratigraphy
-Main Relative Dating Method
-is the study of layers of rocks or the objects embedded within those layers.
-based on the assumption that deeper layers were deposited earlier, and thus are older than more shallow layers.
Seriation
is the ordering of objects according to their age.
James Ford - used seriation to determine the chronological order of American Indian pottery styles in the Mississippi Valley.
Absolute dating * any method of measuring the age of an event or object in years. * To determine the absolute ages of fossils and rocks, * scientists analyze isotopes of radioactive elements.
Isotopes
* atoms of the same element that have the same number of protons but different numbers of neutrons. * Most isotopes are stable, meaning that they stay in their original form. * Other isotopes are unstable. * Scientists call unstable isotopes radioactive.
Radioactive decay * Radioactive isotopes tend to break down into stable isotopes of the same or other elements. * Refers to the process in which a radioactive form of an element is converted into a decay product at a regular rate.
- This dating is not a single method of absolute dating but instead a group of related methods for absolute dating of samples. * Because radioactive decay occurs at a steady rate, * Scientists can use the relative amounts of stable and unstable isotopes present in an object to determine the object’s age.
Dating Rocks — How Does It Work? * In radioactive decay, an unstable radioactive isotope of one element breaks down into a stable isotope. * The stable isotope may be of the same element or of a
Dating techniques are procedures used by scientists to determine the age of a specimen.
2 types of Dating:
*Relative Dating
*Absolute Dating
Relative Dating -methods tell only if one sample is older or younger than another sample.
-They do not provide an age in years.
Stratigraphy
-Main Relative Dating Method
-is the study of layers of rocks or the objects embedded within those layers.
-based on the assumption that deeper layers were deposited earlier, and thus are older than more shallow layers.
Seriation
is the ordering of objects according to their age.
James Ford - used seriation to determine the chronological order of American Indian pottery styles in the Mississippi Valley.
Absolute dating * any method of measuring the age of an event or object in years. * To determine the absolute ages of fossils and rocks, * scientists analyze isotopes of radioactive elements.
Isotopes
* atoms of the same element that have the same number of protons but different numbers of neutrons. * Most isotopes are stable, meaning that they stay in their original form. * Other isotopes are unstable. * Scientists call unstable isotopes radioactive.
Radioactive decay * Radioactive isotopes tend to break down into stable isotopes of the same or other elements. * Refers to the process in which a radioactive form of an element is converted into a decay product at a regular rate.
- This dating is not a single method of absolute dating but instead a group of related methods for absolute dating of samples. * Because radioactive decay occurs at a steady rate, * Scientists can use the relative amounts of stable and unstable isotopes present in an object to determine the object’s age.
Dating Rocks — How Does It Work? * In radioactive decay, an unstable radioactive isotope of one element breaks down into a stable isotope. * The stable isotope may be of the same element or of a