Scientific Method
The first step of the scientific method is making an _______
observation
The Earth is approximately _____ years old.
4.6 billion
This Hypothesis details the likely sequence of events in the formation of our Solar System.
Nebular Hypothesis
This layer of Earth is the shallowest.
crust
The longest segments of geologic time are called ____.
eons
Before beginning an experiment, it is important to come up with a ________.
hypothesis
The idea that geologic events occur uniformly and regularly is known as _________.
uniformitarianism
These planets tend to exist closer to the home star (e.g., our Sun).
rocky planets
This layer of Earth is the hottest and contains solid metal.
inner core
The smallest segment of geologic time is called ____.
epoch
This variable is the one being actively tested in an experiment.
dependent variable
The idea that segments of Earth history have been separated by major events, as evidenced by the fossil record, is known as _______.
catastrophism
These planets are less dense and tend to exist farther away from the home star.
gas planets
This layer of Earth contains most of Earth's mass and volume.
mantle
This segment of geologic time is typically shorter than an eon, but longer than a period.
era
This variable is manipulated for the purposes of an experiment.
independent variable
The evolution of this group of plants led to a significant increase in biodiversity.
flowers
These celestial features brought water to Earth from outer space.
comets
Forces from the outer core create this invisible shield surrounding the Earth.
magnetosphere
The Hadean is an example of a(n) _____.
eon
This variable is kept constant during an experiment.
control variable
coal
Comets may have carried water to the Earth during this violent period of early Earth history, around 4 billion years ago.
Late Heavy Bombardment
Sea ice melting into the ocean is an interaction between these two Earth spheres.
cryosphere, hydrosphere
The Ordovician is an example of a(n) ___.
period