About 99% of the atmosphere is composed of

a. argon and carbon dioxide.

b. nitrogen and water vapor.

c. oxygen and carbon dioxide.

d. nitrogen and oxygen.

When electrons are transferred between two atoms, a covalent bond is formed. true or false

A student needs to use the metric system while measuring the length of a box. Which units should he use?

What is the speed of a walking person in m/s if the person travels 1000 m in 1200 seconds?

Scientists compare the constant motion and cooperating, flowing rhythmic movement of particles to the idea of dance. Santhanam Nagarajan states "Physicists speak of the continuous dance of sub-atomic matter which goes on all the time.

How to identify a superconductor

Which statement is correct about gasoline when it is burned? Heat energy is created by the gasoline. The total energy of the gasoline decreases. Chemical energy in the gasoline is destroyed. Chemical energy is transformed into heat energy.

The tilt of the Earth's axis of rotation changes over a period of 41,000 years. Which of these statements best predicts a long term effect of the changes in the tilt of the Earth's axis of rotation? a. The Earth's climate would change. b.

What do keratinized cells form?

Explain why Planck's introduction of quantization accounted for the properties of black-body radiation.

How and which waves travel either through a medium or a vacuum?