L6. RADIOMETRIC DATING

Question 1

a method used for sequencing rock layers, fossils, and geologic events of the earth

Answer 1

RELATIVE DATING

Question 2

determines the sequence of events and their relative ages, but does not provide a specific numerical age.

Answer 2

RELATIVE DATING

Question 3

Uses the following:
- Stratigraphy
- fossil correlation
- the principle of cross-cutting relationships

Answer 3

RELATIVE DATING

Question 4

Example: Determining that one rock layer is older than another based on their position in a sequence.

Answer 4

RELATIVE DATING

Question 5

a method used to date materials by comparing the abundance of a radioactive isotope to its decay products

Answer 5

ABSOLUTE DATING

Question 6

crucial for determining the age of archaeological and geological specimens.

Answer 6

ABSOLUTE DATING

Question 7

Radioactive Isotopes (6)

Answer 7

Carbon-14 (C-14)
Potassium-40 (K-40)
Uranium-238 (U-238)
Uranium-235 (U-235)
Rubidium-87 (Rb-87)
Thorium-232 (Th-232)

Question 8

Half-life: 5730
Usage: Organic remains up to 50,000 years

Answer 8

C-14

Question 9

Half-life:4.5 billion
Usage: Old rocks and minerals

Answer 9

U-238

Question 10

Half-life: 1.25 billion
Usage: Geological dating

Answer 10

K-40

Question 11

Half-life: 49 billion
Usage: Ancient rocks

Answer 11

Rb-87

Question 12

Half-life: 14 billion
Usage: Geological processes

Answer 12

Th-232

Question 13

Purpose: date relatively recent organic materials (e.g., bones, wood)

Answer 13

CARBON-14
(C-14)

Question 14

Range: effective up to about 50,000 years old.

Answer 14

CARBON-14
(C-14)

Question 15

Use: date artifacts and remains of once-living things.

Answer 15

CARBON-14
(C-14)

Question 16

Living organisms have the same ratio of ___ to ___ as found in the atmosphere

Answer 16

C-12, C-14

Question 17

• Decays into Lead-207.

Answer 17

URANIUM-235

Question 18

the amount of time it takes for half of a sample of that substance to decay or reduce by half.

Answer 18

HALF-LIFE

Question 19

• Useful for dating relatively young rocks (in geological terms) and minerals up to around 1 billion years old.

Answer 19

URANIUM-235

Question 20

Decays into Lead-206.

Answer 20

URANIUM-238

Question 21

Ideal for dating older geological formations, such as rocks billions of years old.

Answer 21

URANIUM-238

Question 22

Decays into Argon-40

Answer 22

POTASSIUM-40

Question 23

Best used for dating igneous rock, ancient geological events, such as the formation of mountain ranges or crustal evolution

Answer 23

POTASSIUM-40

Question 24

Decays into Strontium-87

Answer 24

RUBIDIUM-87

Question 25

Has a half-life of about 48.8 billion years, one of the longest half- lives among radioactive isotopes

Answer 25

RUBIDIUM-87

Question 26

suitable for dating extremely old rocks, from millions to billions of years old.

Answer 26

RUBIDIUM-87

Question 27

Decays into Lead-208

Answer 27

THORIUM-232

Question 28

suitable for dating extremely old rocks, from millions to billions of years old.

Answer 28

THORIUM-232

Question 29

What dating method will you use to date a rock that is estimated to be around 1 billion years old?

Answer 29

ABSOLUTE DATING (POTASSIUM-40 to be more specific)

Question 30

A fossil is estimated to be around 100,000 years old. Can carbon-14 dating be used?

Answer 30

No. Because it is only effective up to about 50,000 years old.

Question 31

oldest fossil ever dated

Answer 31

stromatolites

Question 32

the remains or imprint of an organism that lived during a specific geological time period

Answer 32

index fossil

Question 33

used by scientists to identify and correlate the ages of rock layers (strata) in different locations.

Answer 33

index fossil

Question 34

How old is the Earth

Answer 34

4.5 Billion years

Question 35

Another name for neutron

Answer 35

gluon

Question 36

4 forces

Answer 36

Gravity Electro magnetic Strong nuclear force Weak nuclear force

Question 37

cyanobacteria

Answer 37

stromatolites

Question 38

Age of oldest fossil

Answer 38

3.5 billion years old

Question 39

Age of oldest mineral

Answer 39

4.4 billion years

Question 40

Oldest mineral

Answer 40

Zircon