Earth Science and the Universe Lecture Review

A set of fill-in-the-blank practice flashcards covering soil formation processes, the Big Bang theory, galactic structures, and the physical properties of the universe.

Soil forms as rock is broken down by __________ and mixes with other materials on the surface.

weathering

The __________ horizon develops as plants add organic material to the soil and plant roots weather pieces of rock.

A horizon

The __________ horizon develops as rainwater washes clay and minerals from the A horizon.

B horizon

In the crust of the Earth, Silicon ($Si$) makes up __________ of the composition.

$$28.15\%$$

Around __________ billion years ago, everything in the entire universe was condensed in a small singularity.

$$13.7$$

The cosmos went through a superfast __________ during the first $10^{-43}$ seconds, expanding from the size of an atom to that of a grapefruit.

inflation

By the time the universe was $3$ minutes old, charged __________ and protons prevented light from shining, creating a superhot fog.

electrons

The observation of __________, where visible light bends towards the red end of the spectrum, helped us discover the universe is expanding.

redshift

The scientific study of objects based on the spectrum of color they emit is called __________.

Spectroscopy

The spectrum of visible light coming from an approaching object will shift toward __________.

blue

In Hubble's Law, the velocity of a galaxy is expressed mathematically as __________.

$$v = H \times d$$

The sun itself makes up an estimated __________ of the solar system’s total mass.

$$99.86\%$$

The word "solar" is derived from the Latin word for sun, __________.

Sol

The Milky Way is classified as a large disk-shaped __________ galaxy.

barred spiral

One light year is equivalent to __________ kilometers.

$$9,500,000,000,000$$

The discovery of the Milky Way is credited to the ancient Greek philosopher __________.

Democritus

The ancient Romans called the white streak across the sky the __________, or "road made of milk."

Via Galactica

A __________ is a region of spacetime where gravity is so strong that even light cannot escape.

black hole

To detect black holes, scientists use special instruments to detect the __________ that objects give off as they fall toward it.

heat