1. No category

1. A sample with 35.4% of its
K40 left is how old?
by RL Hanna
1. A sample with 35.4% of its K40 left is how old?
Age=(number of half lives) * (time of one half life)
by RL Hanna
1. A sample with 35.4% of its K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(number of half lives) * (1.3 billion years)
half life data for potassium 40 is from the textbook
by RL Hanna
1. A sample with 35.4% of its K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (1.3 billion years)
Number of half lives = ?
by RL Hanna
1. A sample with 35.4% of its K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (1.3 billion years)
35.4% left => how many half lives?
by RL Hanna
35.4% left => how many half lives?
35.4%
chart by RL Hanna
100%
35.4% left => how many half lives?
50% = 1 half lives
50%
25% = 2 half lives
35.4%
25%
1
2
chart by RL Hanna
35.4% left => 1.5 half lives
35.4%
1.5
chart by RL Hanna
1. A sample with 35.4% of its K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=( 1.5
half lives ) * (1.3 billion years)
35.4%
1.5
chart by RL Hanna
1. A sample with 35.4% of its K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=( 1.5 half lives ) * (1.3 billion years)
Age = 1.5*1.3= 1.95 billion years old
35.4%
1.5
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic ?
63-70 MYA
Mesozoic ?
225-248 MYA
Paleozoic ?
545-600 MYA
A sample with 35.4%
of its K40 left is
1.95 billion years old
What age is the sample?
Crypotozoic ?
3.5-3.8 BYA
Azoic
?
4.5 BYA
Formation of the Earth
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic
63-70 MYA
Mesozoic
225-248 MYA
Paleozoic
545-600 MYA
A sample with 35.4%
of its K40 left is
1.95 billion years old
What age is the sample?
Crypotozoic
1.95 by
3.5-3.8 BYA
Azoic
4.5 BYA
Formation of the Earth
chart by RL Hanna
by RL Hanna
2. Radioactive element Gx75
has a half-life
of 140 million years.
A sample with 10.5% of its
Gx75 left is how old?
by RL Hanna
2. Radioactive element Gx75 has a half-life
of 140 million years.
A sample with 10.5% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
by RL Hanna
2. Radioactive element Gx75 has a half-life
of 140 million years.
A sample with 10.5% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(number of half lives) * (140 million years)
by RL Hanna
2. Radioactive element Gx75 has a half-life
of 140 million years.
A sample with 10.5% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (140 million years)
Number of half lives = ?
by RL Hanna
2. Radioactive element Gx75 has a half-life
of 140 million years.
A sample with 10.5% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (140 million years)
10.5% left => how many half lives?
by RL Hanna
10.5% left => how many half lives?
10.5%
chart by RL Hanna
100%
10.5% left => how many half lives?
25% = 2 half lives
12.5% = 3 half lives
25%
12.5%
10.5%
2
3
chart by RL Hanna
10.5% left => how many half lives?
10.5%
chart by RL Hanna
10.5% left => 3.25 half lives
10.5%
3.25
chart by RL Hanna
2. Radioactive element Gx75 has a half-life
of 140 million years.
A sample with 10.5% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=( 3.25
half lives ) * (140 million years)
10.5%
3.25
chart by RL Hanna
2. Radioactive element Gx75 has a half-life
of 140 million years.
A sample with 10.5% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(3.25 half lives) * (140 million years)
Age = 3.25*140= 455 million years old
10.5%
3.25
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic ?
63-70 MYA
Mesozoic ?
225-248 MYA
Paleozoic ?
545-600 MYA
A sample with 10.5%
of its Gx75 left is
455 million years old
What age is the sample?
Crypotozoic ?
3.5-3.8 BYA
Azoic
?
4.5 BYA
Formation of the Earth
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic
63-70 MYA
Mesozoic
Paleozoic
225-248 MYA
455 my
545-600 MYA
A sample with 10.5%
of its Gx75 left is
455 million years old
What age is the sample?
Crypotozoic
3.5-3.8 BYA
Azoic
4.5 BYA
Formation of the Earth
chart by RL Hanna
by RL Hanna
3. Radioactive element Qg98
has a half-life
of 75 million years.
A sample with 70% of its
Qg98 left is how old?
by RL Hanna
3. Radioactive element Qg98 has a half-life
of 75 million years.
A sample with 70% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
by RL Hanna
3. Radioactive element Qg98 has a half-life
of 75 million years.
A sample with 70% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(number of half lives) * (75 million years)
by RL Hanna
3. Radioactive element Qg98 has a half-life
of 75 million years.
A sample with 70% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (75 million years)
Number of half lives = ?
by RL Hanna
3. Radioactive element Qg98 has a half-life
of 75 million years.
A sample with 70% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (75 million years)
70% left => how many half lives?
by RL Hanna
70% left => how many half lives?
70%
chart by RL Hanna
100%
70% left => how many half lives?
70%
100% = 0 half lives
50%
50% = 1 half life
0
1
chart by RL Hanna
70% left => how many half lives?
70%
chart by RL Hanna
70% left => 0.5 half lives
70%
0.5
chart by RL Hanna
3. Radioactive element Qg98 has a half-life
of 75 million years.
A sample with 70% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
0.5 half life
) * (75 million years)
70%
0.5
chart by RL Hanna
3. Radioactive element Qg98 has a half-life
of 75 million years.
A sample with 70% of its Qg98 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(0.5) * (75 million years) = 37.5 million years old
70%
0.5
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic ?
63-70 MYA
Mesozoic ?
225-248 MYA
Paleozoic ?
545-600 MYA
A sample with 70%
of its Qg98 left is
37.5 million years old
What age is the sample?
Crypotozoic ?
3.5-3.8 BYA
Azoic
?
4.5 BYA
Formation of the Earth
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic 37.5 my
63-70 MYA
Mesozoic
225-248 MYA
Paleozoic
545-600 MYA
A sample with 70%
of its Qg98 left is
37.5 million years old
What age is the sample?
Crypotozoic
3.5-3.8 BYA
Azoic
4.5 BYA
Formation of the Earth
chart by RL Hanna
by RL Hanna
4. Radioactive element Zv99
has a half-life
of 125 million years.
A sample with 42% of its
Zv99 left is how old?
by RL Hanna
4. Radioactive element Zv99 has a half-life
of 125 million years.
A sample with 42% of its Zv99 left is how old?
Age=(number of half lives) * (time of one half life)
by RL Hanna
4. Radioactive element Zv99 has a half-life
of 125 million years.
years
A sample with 42% of its Zv99 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(number of half lives) * (125 million years)
by RL Hanna
4. Radioactive element Zv99 has a half-life
of 125 million years.
A sample with 42% of its Zv99 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (125 million years)
by RL Hanna
4. Radioactive element Zv99 has a half-life
of 125 million years.
A sample with 42% of its Zv99 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (125 million years)
42% left => how many half lives?
by RL Hanna
42% left => how many half lives?
42%
chart by RL Hanna
42% left => how many half lives?
50% = 1 half life
50%
25% = 2 half lives
42%
25%
1
2
chart by RL Hanna
42% left => how many half lives?
42%
chart by RL Hanna
42% left => 1.25 half lives
42%
1.25
chart by RL Hanna
4. Radioactive element Zv99 has a half-life
of 125 million years.
A sample with 42% of its Zv99 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
1.25 half life
) * (125 million years)
42%
1.25
chart by RL Hanna
4. Radioactive element Zv99 has a half-life
of 125 million years.
A sample with 42% of its Zv99 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(1.25) * (125 million years) = 156 million years old
42%
1.25
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic ?
63-70 MYA
Mesozoic ?
225-248 MYA
Paleozoic ?
545-600 MYA
A sample with 42%
of its Zv99 left is
156 million years old
What age is the sample?
Crypotozoic ?
3.5-3.8 BYA
Azoic
?
4.5 BYA
Formation of the Earth
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic
Mesozoic
63-70 MYA
156 my
225-248 MYA
Paleozoic
545-600 MYA
A sample with 42%
of its Zv99 left is
156 million years old
What age is the sample?
Crypotozoic
3.5-3.8 BYA
Azoic
4.5 BYA
Formation of the Earth
chart by RL Hanna
by RL Hanna
5. A sample with 84% of its
K40 left is how old?
by RL Hanna
5. A sample with 84% of its
K40 left is how old?
Age=(number of half lives) * (time of one half life)
by RL Hanna
5. A sample with 84% of its
K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(number of half lives) * (1.3 billion years)
half life data for potassium 40 is from the textbook
by RL Hanna
5. A sample with 84% of its
K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (1.3 billion years)
by RL Hanna
5. A sample with 84% of its
K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
?? ? ?
) * (1.3 billion years)
84% left => how many half lives?
by RL Hanna
84%
84% left => how many half lives?
chart by RL Hanna
100%
84%
84% left => how many half lives?
100% = 0 half lives
50%
50% = 1 half life
0
1
chart by RL Hanna
84%
84% left => how many half lives?
chart by RL Hanna
84%
84% left => 0.25 half lives
0.25
chart by RL Hanna
5. A sample with 84% of its
K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(
0.25 half life
) * (1.3 billion years)
84%
0.25
chart by RL Hanna
5. A sample with 84% of its
K40 left is how old?
Age=(number of half lives) * (time of one half life)
Age=(0.25) * (1.3 billion years) = 325 million years old
84%
0.25
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic ?
63-70 MYA
Mesozoic ?
225-248 MYA
Paleozoic ?
545-600 MYA
A sample with 84%
of its K40 left is
325 million years old
What age is the sample?
Crypotozoic ?
3.5-3.8 BYA
Azoic
?
4.5 BYA
Formation of the Earth
chart by RL Hanna
Phanerozoic
The Geologic Time Scale
0 Today
Cenozoic
63-70 MYA
Mesozoic
Paleozoic
225-248 MYA
325 my
545-600 MYA
A sample with 84%
of its K40 left is
325 million years old
What age is the sample?
Crypotozoic
3.5-3.8 BYA
Azoic
4.5 BYA
Formation of the Earth
chart by RL Hanna
by RL Hanna