Planet Earth

The actual shape of the Earth is most correctly described as

• a circle

• an oblate sphere

• a perfect sphere

• an eccentric ellipse

Which object represents a true scale model of the shape of the Earth?

• a ping-pong ball

• an egg

• a football

• a pear

The equatorial diameter of the Earth is __________ its polar diameter.

• shorter than

• the same length as

• longer than

Which of the following includes the crust and the upper mantle as the rigid outer part of the Earth?

• lithosphere

• hydrosphere

• atmosphere

• stratosphere

Which element in the lithosphere is least abundant by mass?

• oxygen

• magnesium

• silicon

• potassium

Which of the following consists of all the waters on the Earth's surface, such as lakes, rivers and oceans?

• lithosphere

• hydrosphere

• atmosphere

• mesosphere

Which element in the hydrosphere is most abundant by volume?

• oxygen

• helium

• nitrogen

• hydrogen

Which of the following contains the layers of gases that surround the Earth?

• lithosphere

• hydrosphere

• atmosphere

• biosphere

Which layer of the atmosphere has the greatest density?

• troposphere

• stratosphere

• mesosphere

• thermosphere

As altitude increases above sea level, atmospheric pressure __________.

• increases

• decreases

• remains the same