unit 5

Question 1

Evolution

Answer 1

change from simple forms to more complex forms

Question 2

outgassing

Answer 2

Volcanoes began releasing water vapor, carbon dioxide and nitrogen on early Earth

Question 3

Photosyntheis

Answer 3

With carbon dioxide in the atmosphere, photosynthetic organisms were able to evolve

Question 4

Evolution of earth’s atmosphere

Answer 4

1. outgassing
2. photosynthesis, 3.Photosynthesis removed carbon dioxide from the atmosphere and released oxygen
   4.Oxygen led to the evolution of most life forms that exist today

Question 5

Evolution of organisms

Answer 5

Fossil record supports the change from simple to complex life forms

Question 6

How do sci give events/fossils an exact age?

Answer 6

Radioactive decay can be used to give an absolute age

Question 7

isotope

Answer 7

atoms of the same element that have different numbers of neutrons (ex-C12 and C14 are both carbon atoms but C14 has two more)

Question 8

Radioactive decay

Answer 8

an unstable radioactive isotope will break down into another more stable element called a decay product (ex. c14 will decay into N14)

Question 9

Half-life

Answer 9

the amount of time it takes for HALF of the atoms in a radioactive sample to decay

The half-life will never change (even if you apply heat, pressure, break the substance into pieces, etc.

Each time one half-life passes; you divide the amount of radioactive substance remaining in half

Question 10

Carbon 14 half lives

Answer 10

5,700 years, Used to determine the age of “recent” fossils (from the past 50,000 years)

Question 11

Potassium-40 half life

Answer 11

1.3 billion years, Used to determine the age of “old” fossil and rocks

Question 12

Uranium-238 half life

Answer 12

4.5 billion years, Used to determine the age of our Earth and solar system