universe

Current evidence suggests that most of the mass of the universe is in the form of

• black holes

• cosmic rays

• dark matter

• nuclear radiation

Our Sun is just one of many millions of stars in a group of stars called a

• galaxy

• universe

• cosmos

• solar system

Which dominates the atmosphere of Venus?

• nitrogen

• carbon dioxide

• ozone

• benzene

The oxygen in Earth`s atmosphere primarily comes from

• plants

• dissociation of water

• dissociation of carbon dioxide

• fossil fuels

Which of the following is true of our solar system?

• not all known planets orbit in the same direction around the sun

• not all planets spin in the same direction as they orbit

• it has an equal number of stars and planets

• it is less than 1 million years old

In the atmosphere, ____ helps block harmful ultra-violet radiation from the sun that can cause skin cancer.

• oxygen

• nitrogen

• carbon dioxide

• ozone

The moon is no longer geologically active because

• it rotates too slowly

• it is so small that it cooled quickly

• it is too large to be geologically active

• it is does not have surface oceans

Which mineral leave green-black powder when rubbed against an unglazed porcelain plate?

• galena

• hematite

• graphite

• pyrite

Which one among the following rocks does not belong to the same group?

• Shale

• Limestone

• Slate

• Sandstone

Igneous, sedimentary, and metamorphic rocks are usually composed of

• intergrown crystals

• minerals

• fossils

• sediments