Chapter 8 - Geological Time

Question 1

Which is the oldest of the following geological time periods?
A) Silurian
B) Tertiary
C) Permian
D) Ordovician
E) Devonian

Answer 1

D) Ordovician

Question 2

The half-life of a radioactive isotope is:
A) One half the time the sample has been decaying
B) One half the time required for the entire sample to decay
C) The time required for one half of a sample to decay
D) One half the time required for 50% of the sample to decay

Answer 2

C) The time required for one half of a sample to decay

Question 3

Absolute (numerical) dating is based on:
A) The accumulation of radioactive elements
B) The decay of radioactive elements
C) The melting of radioactive elements
D) The freezing of radioactive elements
E) The gasification of radioactive elements

Answer 3

B) The decay of radioactive elements

Question 4

The Mesozoic Era is often called the age of reptiles. It (the Mesozoic) is the time period in Earth's history that ran from about \_\_\_\_\_\_\_.
A) 2500 Ma to 545 Ma
B) 545 Ma to 250 Ma
C) 250 Ma to 65 Ma
D) 65 Ma to 10 Ka
E) 10 Ka to now

Answer 4

C) 250 Ma to 65 Ma

Question 5

The potassium-argon method of dating the age of igneous rocks works because
A) 40^K is lost when a rock melts
B) 40^Ar is lost when a rock melts
C) Both 40^Ar and ^40K are lost when a rock melts
D) 40^K is lost when a magma crystallizes
E) Both 40^K and 40^Ar are formed when a magma crystallizes

Answer 5

D) 40^K is lost when a magma crystallizes