This is the basis of the chemical standard for the quantity of a mole. A. oxygen-16 B. carbon-12 C. hydrogen-1 D. helium-2

If you live in Earth's northern hemisphere, on June 20th or 21st you experience summer solstice, which represents the official start of summer. This is the longest day of the year. What causes this change in day length?

Which of the following reactions is the least energetic? Question 18 options: ATP + H2O → ADP + Pi ATP + H2O → AMP + PPi AMP + H2O → Adenosine + Pi ADP + H2O → AMP + Pi All give off the same amount of energy.

The reaction of 1.250 g k with o2 forms 2.273 g of an oxide of potassium that is used in self-contained breathing devices. determine the formula for this oxide of potassium.

A 1.0-mole sample of krypton gas has a mass of

Why do metals tend become cations?

c. When we heat water up by the Bunsen burner, what temperature is the boiling water? After 10 minutes

Assuming that air contains 78 percent N2, 21 percent O2 and 1 percent Ar, all by volume. How many molecules of each type of gas are present in 1.0 L of air at STP?

Two children are playing tag. Child A who is doing the chasing can run 100m in 24 seconds Child B is running away from child A and can run 64m in 21 seconds.

What ion does a base increase

What is the definition of Amplitude?