Earth's Early History reteach

Nebular Theory

Review for Nebular Theory Quiz

Multiple Choice

A celestial cloud of dust and gas is called . . .

• nebula
• supernova
• accretion disc
• bombardment

Multiple Choice

What is the FIRST event in the formation of the solar system?

• About 4.5 billion years ago pieces of rock and ice accumulate more material until they grow into planets and moons.

• About 4.6 billion years ago, a cloud of stellar dust or nebula exists within the Milky Way.

• None of the above.

Multiple Choice

What force acted on the massive nebula to collapse it and eventually form our sun?

• electrostatic force
• strong force
•  weak force
• gravity

Multiple Choice

The energy enriched nebula begins to contract further due to gravity. Then what?

• The center of the nebula begins to get hot and dense.

• Shock waves hit the nebula causing it to collapse.

• The nebula begins to spin and flatten.

Multiple Choice

The collapsed cloud of interstellar gas and dust results to a smaller radius which means it will _______ faster.

• spin

• degrade

• revolve

• explode

Multiple Choice

when dust and gas gravitate together and form ever larger bodies

• absolution

• attrition

• accretion

• erosion

​planetesimals stick together to form protoplanets

Multiple Choice

The protoplanets keep:

• Colliding and breaking apart
• Colliding and sticking together
• Colliding and bouncing around
• Breaking down into smaller pieces

Multiple Choice

As the solar system continued to evolve, material in the disk collided with other material and grew into planetesimals, then protoplanets, and then planets. This process of growth by collision created a lot of heat, melting the early Earth. Growth by collision is called ___.

• differentiation

• accretion

• adsorption

• kinetic molecular theory

Multiple Choice

Sun + orbiting planets =

• nebula

• solar system

• asteroids

• meteroids

Reorder

Reorder the following

• The nebula started to collapse and condense; this continued for some time.

• Pockets of dust and gas began to collect in denser regions and it began rotating.

• The solar nebula rotated faster and faster as it shrank in radius AND flatten.

• Most of the material ended up in a ball in the middle as the Sun's protostar.

• The rest of the nebula was left in the form of a disk called a protoplanetary disk.

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Heavy Bombardment Period

Asteroids collide with young planets

During the Heavy Bombardment Period failed planets and large asteroids slammed into larger worlds, including young Earth. When these objects struck Earth, they left craters.

Multiple Choice

When did frequent large impacts stop?

• about 9,000 years ago

• about 3 million years ago

• about 9 billion years ago

• about 3.9 billion years ago

Multiple Choice

When the inner planets (and moons) were bombarded by asteroids, what did the asteroids leave behind?

• craters
• calderas
• mountains
• valleys

The earth moves!

Our earth moves! We have many pieces of evidence for this some we can even feel; like earthquakes. So what is causes the movement? Magma! Deep in the Earth, molten rock churns as it heats and cools in convection currents. This moves the crustlike plates on top, and even creates and new and destroys old plates. *VIDEO TIME*

One problem with dating rocks and minerals on Earth is the presence of the rock cycle. During the rock cycle, rocks are constantly changing between forms, going back and forth from igneous to metamorphic to sedimentary. Old rocks may even be destroyed as they slide back into the Earth's mantle, to be replaced by newer rocks formed by solidified lava. This makes finding an exact age for the Earth difficult, because the original rocks that formed on the Earth at the earliest stages of its creation are no longer here. The oldest rocks that have been found are about 3.8 billion years old, though some tiny minerals have been dated at 4.2 billion years.

To get around the difficulty presented by the rock cycle, scientists have looked elsewhere in the solar system for even older rock samples. They have examined rocks from the moon and from meteorites, neither of which have been altered by the rock cycle. The same techniques of radiometric dating have been used on those rocks. All of the data from this planet and beyond has led to the estimated age for the Earth of 4.5 billion years.

Multiple Choice

Scientists currently estimate that Earth is approximately ____ years old.

• 600 years old

• 4.5 million years

• 4.5 billion years

• 53 million years

Multiple Choice

How long has the recycling of Earth’s crust been going on?

• about 4 billion years

• about 4,000 years

• about 4 million years

• about 400 years

Multiple Choice

Meteorites have clues about our planet's past.

• true
• false

Multiple Choice

Why are meteorites important to evidence when estimating the age of Earth?

• Meteorites are most likely debris ejected from the sun and moon.

• Meteorites come from bodies in space that formed along with the planets and are thought to have similar compositions to Earth's layers.

• Meteorites formed far outside the solar system at the same time Earth formed.

Dropdown

It wasn't until we went to the​​

Select answer

in 1969 that scientists were able to find​

Select answer

of the age of Earth​.

Drag and Drop

Moon formed from a​

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colliding with Earth during the ​

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. This means the rocks on the ​

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are ​

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Earth, since they formed at ​

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time.

Drag these tiles and drop them in the correct blank above

protoplanet

Heavy Bombardment Period

Moon

the same age as

asteroid

Accretion Disk

older than

younger than

the same

a different

Multiple Choice

Why is Moon covered with craters, but Earth is not?

• Moon has no tectonic activity.

• More asteroids hit Moon than Earth

• Moon is older than Earth

• most asteroids land in Earth's oceans

Multiple Choice

Why is Moon covered with craters, but Earth is not?

• Earth's atmosphere protects Earth and weathers craters away

• Earth's moon blocks asteroids
• asteroids just missed Earth
• Moon's rocks are harder to wear away than Earth's

Multiple Choice

True or False: Earth, Moon, and all the other objects in the solar system (meteorites, asteroids, other planets) are all the same age since they all formed at about the same time.

• True

• False

Multiple Choice

T/F: Geologists can use radioactive dating to find the absolute age of rocks

• True
• False

Multiple Choice

The radiometric dating of an igneous rock provides ____________.

• the relative age of the rock
• the age of Earth
• a date for when the rock formed
• a date for when the rock was eroded

Multiple Choice

When S-waves reach the outer core of the Earth they stop and when P-waves reach the outer core of the Earth they slow down. What is the reason for this speed change?

• The outer core is a solid and P-waves don't go through solids.

• The outer core is a liquid and P-waves slow down in liquids and S-waves don't go through liquids.

• The outer core is made of iron and S-waves don't go through iron and P-waves always slow down in iron.

• The outer core is a putty-like material and S-waves don't go through putty and P-waves slow down in putty like material.