CALCULATING HALF-LIFE Aim: How can we measure how much of a radioactive element decayed? DO NOW: If we start with 4.5 grams of Radon- 222 and over a period.

Slides:

Advertisements

Similar presentations

Half-Life and Radioisotope Dating

Advertisements

Mr. ShieldsRegents Chemistry U02 L03 Nuclear Decay Series Uranium has an atomic number greater than 83. Therefore it is naturally radioactive. Most abundant.

Radioactivity and Half-Life

Aim: What is the half-life of a radioisotope Do Now:

Growth and Decay. The Half-Life Time of a Radioactive Elements.

Absolute Dating of Rocks and Strata

Exponential Growth and Decay 6.4. Exponential Decay Exponential Decay is very similar to Exponential Growth. The only difference in the model is that.

Chapter 18.  Mass # Symbol  Element Name or symbol – Mass #  Parts of a Reaction Reactants  Products.

Nuclear Chemistry.

Nuclear Chemistry Ch 18, Pg 666, # 1-8

Half-Life Nuclear Chemistry. What is Half-Life? The time it takes for half of a given amount of a radioactive isotope to undergo decay.

Half Life Practice.

1 Radioactivity and Half-Life. 2 Radioactivity An unstable atomic nucleus emits a form of radiation (alpha, beta, or gamma) to become stable. In other.

Unit 2: The Atom Half- Life. Half Life The time required for one half of the nuclei of a radioactive isotope sample to decay to atoms of a new element.

7.2 Half-Life the time it takes for half of a radioactive sample to decay is a constant rate (always the same half life for each element) Example: Strontium-90.

Half-Life Definition Half-life: the TIME it takes for half of a radioisotope sample to ‘decay’ and become another element. What are the three ways this.

Determining Absolute Time.  Absolute Time: numerical time using a specific units like years  Isotopes: Form of an element with more or fewer neutrons.

Radioactive Decay. I can solve half-life problems. Radioisotopes decay in a predictable way – The time is takes for half of a sample to decay is called.

Chapter 4.1. Half-Life Original Sample One half-life Two half-lives Three half-lives Contains a certain One-half of the One-fourth of One-eight of the.

Copyright © 2014 All rights reserved, Government of Newfoundland and Labrador Earth Systems 3209 Unit: 2 Historical Geology Reference: Chapters 6, 8; Appendix.

Review. What type of decay will happen if the nucleus contains too many neutrons? Beta Decay.

Half Life EQ: How is the half-life of a radioactive element used to determine how much of a sample is left after a given period of time?

Radioisotopes The nuclei of some atoms are unstable and undergo spontaneous changes called radioactive decay. One such change is called beta decay. During.

Half- Life. Some minerals contain radioactive elements. Some minerals contain radioactive elements. The rate at which these elements decay (turn into.

Relative Dating and Fossils Relative dating Relative dating Law of Superposition Law of Superposition Index Fossils Index Fossils What are fossils? What.

The fossil below is that of a Coelophysis and was found in upstate N.Y. Approximately how old is the rock?

Dating Rocks and Remains Radioactive Decay: Vocabulary Half-Life: The amount of time it takes for half of a radioactive isotope to decay. Radioactive.

Isotopes and Radioactivity

Some elements have atoms which are unstable. These atoms spontaneously transmutate from one element to another. These types of transmutations include.

Absolute Dating.

Radioactive Decay Radioactive materials decay from the “Parent” material into the “Daughter Product”. Original “Parent” Material Daughter Product.

NUCLEAR HALF LIFE. T ½ The half life is the amount of time it takes for half of the atoms in a sample to decay. The half life for a given isotope is always.

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 9 Nuclear.

Chapter 7.2 – Half life Science 10. Types of decay Alpha Alpha.

Half Life Calculation of Radioactive Decay Atomic Physics.

Half-life.  Half-Life - the time required for one half of a sample of a radioisotope to decay, while the other half remains unchanged  Half-lives vary.

Rates of Nuclear Decay Chapter 10 Section 2 Pg

Radioactive Decay.

Do Now Which nuclear emission has the greatest mass and the least penetrating power? an alpha particle 2. a beta particle a neutron 4. a positron When.

Example 1 Using Zero and Negative Exponents a. 5 0

Wednesday, November 4 th, 2015 The blue grid below represents a quantity of C 14. Each time you click, one half-life goes by and turns red. C 14 – blue.

Radiometric Dating Chapter 18 Geology. Absolute Dating Gives a numerical age Works best with igneous rocks difficult with sedimentary rocks Uses isotopes.

Radiometric Dating “clocks in rocks”. Absolute Dating Gives a numerical age Gives a numerical age Works best with igneous rocks & fossils Works best with.

Unit: Nuclear Chemistry Half-Life Day 2 – Notes. After today you will be able to… Identify the factor that nuclear stability is dependent on. Calculate.

 Radioactive Decay Bedrock Day 5 – March 1, 2013.

Nuclear Chemistry II. Radioactive Decay C. Half-Life II. Radioactive Decay C. Half-Life.

UNIT 7 NUCLEAR REACTIONS 7.3 Calculating Half Life? May 17, 2011 DO NOW: = /4.5 = If we start with 4.5 grams of Radon-222 and over a period.

Radioactive Decay and Half-Life. The isotope Radium–228 undergoes beta decay as shown in the following equation:

 Half-life – the time it takes for ½ of a radioactive sample to decay  Half-life for a radioactive element is a constant rate of decay  Half-life differs.

Radioactive Decay. Types of Radioactive Decay Alpha Decay: nucleus eject an alpha particle (made of 2 protons and 2 neutrons – a helium nucleus)

Holt McDougal Algebra Exponential Growth and Decay Warm Up Simplify each expression. 1. ( ) The first term of a geometric sequence.

Do First Actions: Turn in yesterday’s worksheet 1. List the layers from youngest to oldest.

Half Life Calculations Aim Nuke 5e – How long does radioactivity last?

Masses of Atoms and the Periodic Table. Atomic number To identify which element an atom is, we look at the number of protons. The number of protons in.

Friday Dec 12 Objective: Calculate the half-life of radioactive materials. Checkpoint: What is the half-life of a radioactive sample if it takes 10 years.

Half-Life and Nuclear Stability. How many isotopes are stable? So far, 118 different elements have been isolated. Only 92 of these are naturally occurring;

 Reactions that affect the nucleus  Can change the identity of the element (if number of protons change)

Radioactive Isotopes and Half Life 1. I can explain what a Radioactive Half-Life is and do a calculation with both a T-table and by equation. 2.

Topic: Nuclear Chemistry

EMPIRICAL FORMULA The empirical formula represents the smallest ratio of atoms present in a compound. The molecular formula gives the total number of atoms.

100% 50% 25% Each half life reduces the mass of the sample by half. Calculate the half life of a substance if 12.5 % of it remains after 90 years?

Time it takes for 1/2 of the radioactive atoms in a sample to decay.

Radioactivity, Half-life, and Nuclear Reactions

Geologic Time and Earth History Part 2 – Absolute Age

Presentation transcript:

CALCULATING HALF-LIFE Aim: How can we measure how much of a radioactive element decayed? DO NOW: If we start with 4.5 grams of Radon- 222 and over a period of time we have 3.4 grams left over. What is the fraction remaining of this sample? 3.4g / 4.5g =

What is half-life? The amount of time it takes for the mass of a radioactive sample to decay by half. Half-life is AMOUNT OF TIME Table N

EXAMPLE!! Consider a 10 g sample of Au-198. (Table N)  What decay mode does Au-198 have? (3) Alpha decay!  What half-life does Au-198 have? (4) 2.69 days

Let’s see Au-198 At 0 half-life or 0 days, there are 10 g present. After 1 half-life or 2.69 days, there are 5 g remaining. After 2 half-life or 5.38 (2 x 2.69) days, (5) 2.5grams remain. After 3 half-life or 8.07 (3 x 2.69) days, (6) 1.25 grams remain.

Calculating Fraction Remaining… What is a fraction? THE RATIO BETWEEN A PART AND A WHOLE. …NOW I NEED 8 VOLUNTEERS

Fraction Remaining # of Half-LivesFraction Remaining 01 1½ 2¼ 31/8 41/16 51/32

Example 1 If 1.00 gram of a gram sample of sodium-25 remains unchanged after 237 seconds, what is the fraction remaining? Step 1: What was the mass of the original sample?  gram Step 2: What is the mass that is remaining after the given period of time?  1.00 grams Step 3: What is the fraction remaining?  1/16

EXAMPLE 3 If 1.00 gram of a gram sample of sodium-25 remains unchanged after 237 seconds, how many half-lives have passed? Step 1: What was the mass of the original sample?  grams Step 2: What is the mass that is remaining after the given period of time?  1.00 grams Step 3: What is the fraction remaining?  1/16 Step 4: How many half-lives have passed?  4

Calculating total time FORMULA: # of half-lives x length of half-life = total time

Example 6 A sample of wood is found to contain 1/8 as much C-14 as ipresent in the wood of a living tree. How old is the tree? Step 1: Figure out the fraction remaining.  1/8 Step 2: Figure out the number of half- lives passed.  3 Step 3: Figure out the length of one half-life (Table N or given in the problem).  Step 4: Multiply the number of half-lives by the length of one half-life. 3 x =