Which measurement below has three significant figures? a) 0.018km b) 12.02m c) 0.2004g d) 12,300lbs

To what chemical reaction class does this reaction belong? 2 mg (s) + o2 (g) 2 mgo (s)

Propane (c3h8) burns in oxygen to produce carbon dioxide gas and water vapor. (a) write a balanced equation for this reaction. (use the lowest possible coefficients. include states-of-matter under the given conditions in your answer.)

Sodium (na) is a highly reactive metal and chlorine is a poisonous gas. Which compound do they form when they chemically combine?

For which one of the following is ΔHfo zero? A. O (g) B. Na (s) C. CO2 (s) D. N2 (l)

What is the mass of 6.02x10^23 potassium atoms?

Read the two questions. Question 1: Should acid precipitation be a concern for the new age environmentalist? Question 2: Does acid precipitation in forests affect the reproduction rate in birds?

How is excitation in spectroscopy brought about

What is the best reason for a student to remove a dangling bracelet when heating test tubes of acidic solutions in a hot-water bath in a chemistry lab?

What does the electron cloud model describe A. Rapidly moving neutrons B. Rapidly moving protons C. A standing wave of electron wavicles surrounding the nucleus D. Rapidly moving nucleus

35mL of acid with an unknown concentration is titrated to completion using 63mL of 3.0 MNaOH. What is the concentration of the acid?