Which is NOT a tool once used by navigators to determine their latitude?

Which of the following is NOT one of the thirteen zodiac constellations?

Who proposed the heliocentric theory of the solar system?

Which type of bond occurs when atoms share electrons?

Which chemist is credited with the discovery of oxygen?

Which element does NOT take its name from Greek or Roman mythology?

What is the heaviest naturally-occurring element found on the periodic table?

What is the most common state of matter in the universe?

Which subatomic particle allows atoms to form bonds?

The work of ___________ led to the banning of pesticides containing DDT.

A __________ is a place where a population of organisms lives in an ecosystem.

Earth is composed of four subsystems called "spheres." Which is NOT one of Earth's spheres?

Which of the following is NOT a gas that is responsible for the greenhouse effect?