Chemistry - Radiometric Dating

Question 1

Radiometric Dating

Answer 1

This is the method of dating speciments by determination of relative proportions of particular radioactive isotopes in the sample.

Question 2

How is C14 produced

Answer 2

Cosmic ray impacts knocking nitrogen protons loose

Question 3

Cosmic Ray

Answer 3

Highly energetic atomic nuclei travelling through space at speed approaching that of light.

Question 4

What happens to C14 when it is produced?

Answer 4

It distributes along the carbon cycle, decaying by electron emission.

Question 5

Why are geiger counters inefficient?

Answer 5

Inhibition by other radioactive particles.

Question 6

What are the three ways C14 is measured?

Answer 6

Gas Proportional Counting
Liquid Scintillation Counting
Accelerator Mass Spectrometry

Question 7

Gas Proportional Counting

Answer 7

Proportional counters are gaseos ionization detectors that measure particles of ionizing radiations.

Question 8

Liquid Scintilattion Counting

Answer 8

This measures beta-meitting and alpha-emitting isotopes, liquidifying sample carbon to benzene, then measuring radioacitvity in a scintillation counter.

Question 9

How do scintillation counters work?

Answer 9

Detecting/measuring ionizing radiation by using incident radiation excitation.

Question 10

Scintillator

Answer 10

A material with the property of luminescense, scintillating, when excited by ionizing radiation.

Question 11

What happens when a scintillator detects incident radiation?

Answer 11

Generates protons where a photodetector converts light into an electrical signal.

Question 12

Photodetector

Answer 12

This detects/responds to incident light by sing photon electrical effects.

Question 13

Accelerator Mass Spectrometry

Answer 13

This is a mass spectrometer that accelerates ions to extrdinarily high kinetic energies before mass analysis.

Question 14

Mass Spectrometers

Answer 14

Measure mass-to-charge ratio before mass analysis

Question 15

What ages does radiocarbon dating produce?

Answer 15

Radiocarbon years, which must be callibrated to calendar years.

Question 16

What is the most common form of radiometric callibration?

Answer 16

Tree trings

Question 17

What is an example of tree dating?

Answer 17

Maunder minium, sun spots dramatically decreased, tree trings showed ratio of C14/C increased.

Question 18

Why does C14/C ratio increase with increased dsolar radiation?

Answer 18

Ion increase and heliospheric magnetic field

Question 19

Heliospheric magnetic field

Answer 19

Component of the solar magnetic field dragged out from the solar corona by the solar wind flow to fill the solar systems

Question 20

What is a potential cause of the holocene?

Answer 20

Earths magnetic field change deflecting sun rays.

Question 21

How are magnetic fields measured?

Answer 21

Magnetic chronology

Question 22

How was carbon dating used as proof for TC shutodwn cause of YD?

Answer 22

C14/C increased bt 5% during first 200 years, then drifted back down during remaining 1000 years

Question 23

How can past radiacne measured?

Answer 23

Solar irradiance is tied in C14 increase

Question 24

How did C14 related to hydrogen bombinb ing 50s/60s

Answer 24

Released neutrons collided with atmospheric nitrogen doubled C14 ratios

Question 25

Beta Decay

Answer 25

This is the emission of electrons or positrongs, or process of electron capture.

Question 26

Half life

Answer 26

This is the rate at which it takes half the material of an atom to decay.

Question 27

What happens after 10 half lives of c14

Answer 27

57,300 years amount is about 0.1%, too hard to detect

Question 28

How does C14 relate to age of an object?

Answer 28

Older artifacts have less C14 than younger ones.