The gas used to fill party ballons contain only helium atoms. This make helium a (n).

A parallel connection of several lamps in a home allows you to control each lamp independently with switches. How is this possible?

Carol is in a railroad car on a train moving west along a straight stretch of track at a constant speed of 120 km/h, and Charles is in a railroad car on a train at rest on a siding along the same stretch of track.

What determines the current phase of the moon? * A. The seasons B. How much of the sunlit part of the moon is visible C. The 23.5 degree tilt of the Earth D. The side of the moon facing Earth

What are two ways to find wavelengths

Which of these is NOT a mixture? A) baking soda B) salt and water C) iron filings and sand D) metal paper clips and plastic paper clips

Ina shoots a large marble (Marble A, mass: 0.08 kg) at a smaller marble (Marble B, mass: 0.05 kg) that is sitting still. Marble A was initially moving at a velocity of 0.5 m/s, but after the collision it has a velocity of - 0.1 m/s.

The elements that touch the zigzag line ar classified as

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