Which was least likely to have been a component of Earth's atmosphere before life began?

A-sulfur

B-carbon dioxide

C-oxygen

D-water vapor

Name an organic molecule that carbon is found in.

According to newton's third law, when a horse pulls on a cart, the cart pulls back on the horse with an equal force on the horse.

Wave A has an amplitude of 2 and wave B has an amplitude of 2 as shown below. What will happen when the crest of wave A meets the trough of wave B? They will interfere to create a crest with an amplitude of 4.

How is the sound quality of an instrument related to the overtones it produces?

In an h-r diagram most stars are found in a diagonal band from the upper left to lower right which is called?

The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have passed? A. 25 g B. 100 g C. 75 g D. 50 g

During a transit, a passes in front of its parent star, temporarily decreasing the star's brightness by a small amount.

How much of each food dollar goes to the producer

What is the effect of a magnetic field on a stationary electric charge on a moving electric charge?

A ball is thrown upwards with an initial velocity of 25. o m/s, what is the velocity of the ball at 11.9 m from the ground?