Academic/ELL Earth Science AGENDAApril 19, Thursday: B Day

Take out your Geologic Time Activity (Geology 12 CH#8 Worksheet)WARM-UPS: Do the following with 1 or 2 people:

1. Differentiate between absolute and relative timea. Give examples of each

2. What is an isotope? (8th grade physical science)3. Describe a radioactive element.

a. Give an example4. Define half-life

ExC-ELL vocabulary exerciseCONTENT OBJECTIVE: The student will investigate and understand that many aspects of the history and evolution of Earth and life can be inferred by studying rocks and fossils. Key concepts include a) traces and remains of ancient, often extinct, life are preserved by various means in many sedimentary rocks; b) superposition, cross-cutting relationships, index fossils, and radioactive decay are methods of dating bodies of rock; c) absolute and relative dating have different applications but can be used together to determine the age of rocks and structures; and d) rocks and fossils from many different geologic periods and epochs are found in Virginia.

Language OBJECTIVE: today you will1. Differentiate between absolute and relative time2. Apply the Laws of “Superposition, Cross-cutting relationships, and Inclusions to order rock

layers from oldest to youngest3. Determine the number of half-lives from percentage of parent/daught isotopes in materials

OBJECTIVES: Geologic TIME (Historical Geology)1. HOMEWORK CHECK

a. Laws of Superposition, Cross-cutting relationships, and Inclusions – CORRECT your work if necessary – identify the “Law” that applies

2. ABSOLUTE time: Short videohttps://www.youtube.com/watch?v=phZeE7Att_shttps://www.youtube.com/watch?v=Kcuz1JiMk9k https://www.youtube.com/watch?v=Kn84C1aBC4s https://www.youtube.com/watch?v=n8Cru41w5uI

radioactive decay is the disintegration of an unstable atom with an accompanying emission of radiation. As a radioisotope atom decays to a more stable atom, it emits radiation only once.

3. PRACTICE: attached4. CLOZE Activity

HOMEWORK:

1. Complete the Geology QUIZ Review: Geologic time scale, relative and absolute age

Parent

Daughter t1/2 Useful Range Type of Material

238U 206Pb 4.5 b.y

>10 million years

Igneous Rocks and Minerals

235U 207Pb 710 m.y

232Th 208Pb 14 b.y

40K40Ar & 40Ca

1.3 b.y >10,000 years

87Rb 87Sr 47 b.y >10 million years

14C 14N 5,730 y 100 - 70,000 years Organic Material

PRACTICE:

1. How much parent isotope is left after 1 half-life? How much daughter isotope is present?

2. After 3 half-lives, what is the ration of parent isotope to daughter isotope?

3. The half-life of C14 is 5,700 years. How old is a bone if 3 half-lives have occurred?

4. How many half-lives have passed if a bone is 11,400 yrs old? What is the RATIO of parent to daughter isotope?

5. A rock has the ratio of ¼ parent to ¾ daughter isotope. How many ½ lives have occurred since the formation of the rock?

Review of concepts:

Geologic Time Scale & Relative Time Quiz review

1. List the rock layers in order from OLDEST to YOUNGESTa. Identify the geologic principle that explains the order (superposition, cross-cutting

relationships, etc)

1. Use your geologic time scale notes to complete the following:

_____________________a. Age of Mammals

_____________________b. Age of Reptiles

_____________________c. Age of Invertebrates

_____________________d. These 2 time periods make up the Carboniferous

_____________________

_____________________d. These organisms were dominant during the Age of Invertebrates

_____________________e. Break-up of Pangaea

_____________________f. Humans appeared (time period and Epoch)

_____________________

_____________________ g. List the ERAS where the only events were associated with the formation of

______________________ the EARTH

_____________________ h. Identify the era and time period of the dinosaur extinction

i. List the ERAS associated with the development of ANY TYPE of life forms.

3. Differentiate between absolute and relative time

List the methods/describe the laws to determine BOTH

Superposition & Cross-cutting Relationships

James Hutton – the “Father of Geology” , developed the Law of Uniformitarianism = the Present is the key to the Past or the processes acting in the present to form the rocks & physical features of the Earth are the same processes that formed the rocks and physical features of the Earth in the past. Previously, people believed that mountains, canyons, and other features were the result of cataclysmic events.

Relative Time: A comparison based on age of rock layers. Relative time is measured as “older” or “younger”. Absolute time is more exact – age is measured in specific units of time (thousands or millions of years old). Law of Superposition – A measure of relative time = in undisturbed, sedimentary rock layers, the older rocks are on the bottom, and younger layers are on top. Law of Cross-cutting relationships – also a measure of relative time = Layers that cut through pre-existing layers (igneous intrusions) are younger than the layers they cut through. (If you have an “intruder” in a building, the building has to be there BEFORE the person can go INTO it).Faults – faults are younger than the pre-existing layers

Law of Inclusions

The Law of Inclusions was also described by James Hutton and stated that if a rock body (Rock B) contained fragments of another rock body (Rock A), it must be younger than the fragments of rock it contained. The intruding rock (Rock A) must have been there first to provide the fragments.

http://legacy.belmont.sd62.bc.ca/teacher/geology12/assignments/Chapter%208%20WS%201%20-%20KEY.pdf

Definition Characteristics/facts

Example Picture or Word ART

DefinitionCharacteristics/facts

Example Picture or Word ART

Absolute time

Absolute time is the measurement taken from the same rocks to determine the amount of time that has expired. It is expressed as a number.

Relative time

Relative time is a comparison between older and younger rock layers. Older layers are under younger layers

Example Picture or Word ART

Definition Characteristics/facts

Example Picture or Word ART

Half-Life

Radioactive Decay

process by which an unstable atomic nucleus (parent isotope) loses energy by emitting radiation, forming a daughter isotope

 process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron ...

Radioactive (disambiguation) · Particle decay · Radiation · Internal conversion

What is Radioactive Decay - Definition - What is Nuclear Powerhttps://www.nuclear-power.net/nuclear-power/reactor...nuclear.../radioactive-decay/

1.Nuclear decay (Radioactive decay) occurs when an unstable atom loses energy by emitting ionizing radiation. ... Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus. ... Neutron emission is a type of radioactive decay of ...

What is Radioactive Decay · Radioactive Decay Law

Radioactive decay - definition of radioactive decay by The Free ...https://www.thefreedictionary.com/radioactive+decay

1.· tive decay. (rā′dē-ō-ăk′tĭv) The spontaneous breakdown of a radioactive nucleus into a lighter nucleus.Radioactive decay causes the release of radiation in the form of alpha particles, beta particles, or gamma rays.

Radioactive Decay - NDT Resource Centerhttps://www.nde-ed.org/EducationResources/HighSchool/.../radioactivedecay.htm

1.2.

RADIOACTIVE DECAY. After reading this section you will be able to do the following: Describeradioactive decay and transmutation. Discuss the two forms of radiation that can be released due toradioactive decay. What is radioactive decay? Radioactive decay is the spontaneous breakdown of an atomic nucleus resulting ...

What is Radioactive Decay? - Definition from Safeopediahttps://www.safeopedia.com/definition/2919/radioactive-decay

1.Radioactive Decay Definition - Radioactive decay is used to describe what happens to the nucleus of an unstable atom when it loses energy and emits...

What is RADIOACTIVE DECAY? What does RADIOACTIVE DECAY ...▶ 3:58

https://www.youtube.com/watch?v=3ydVv6DeZZI

1.Aug 20, 2016 - Uploaded by The Audiopedia

What does RADIOACTIVE DECAY mean? RADIOACTIVE DECAY meaning -RADIOACTIVE DECAY ...

Radioactive Decay: Definition, Formula & Types - Video & Lesson ...https://study.com/academy/lesson/radioactive-decay-definition-formula-types.html

1.2.

process by which an unstable atomic nucleus (parent isotope) loses energy by emitting radiation, forming a daughter isotope