Astronomy

How long does it take Earth to complete one rotation on its axis?

• 12 hours

• 24 hours

• 365.25 days

• 29.5 days

Less solar radiation reaching Earth will result in...

• increased incidences of skin cancer

• decreased rates of photosynthesis

• increased phytoplankton activity

• decreased carbon dioxide levels

Why do plants require sunlight?

• to make their own food

• to absorb nitrogen into their roots

• to release carbon dioxide into the atmosphere

• to decompose the dead or decaying remains of an animal

Where does fusion occur?

• core of the sun

• on earth

• nuclear power plants

Which will impact tides on Earth more?

• the sun

• the moon

Which of these is the main source of electromagnetic energy we use?

• battery

• wind

• sun

• coal

Why do we have changes in season?

• rotation of earth on its axis

• tilt of earth's axis of rotation

• the distance of earth from the sun

• the size and orbit of the moon around the earth

What are the two most prominent gases in stars?

• helium

• oxygen

• nitrogen

• hydrogen

Where do hours of daylight remain constant?

• the poles

• the equator

• North America

• Canada

The length of a year is determined by

• revolution

• rotation