Calculate the frequency (in Hertz) of light with a wavelength of 420 nm. What color is the light?

Elements for NaC1 (5)

When you rub your hands together on a cold day, what energy transformation is taking place?

You have 2.394 x 102 mL of oxygen gas (O2) at 7.20 x 102 mm of Hg and 78 oC. What is the mass of the sample in milligrams?

Galena is the ore from which elemental lead is extracted. in the first step of the extraction process, galena is heated in air to form lead (ii) oxide. 2pbs (s) + 3o2 (g)  2pbo (s) + 2so2 (g) h = - 827.

How does the arrangement of graphite allow a pencil to make a mark

There is a large increase in ionization energy between the second and the third ionization energies of a metal. What kind of ion is the metal likely to form? Include the charge in your answer.

Which of the following are true statements about equilibrium systems? For the following reaction at equilibrium: CaCO3 (s) ⇌ CaO (s) + CO2 (g) adding more CaCO3 will shift the equilibrium to the right.

How many sulfide ions are present in 23.5g of Sb2S3

2. An automobile tire has a pressure of 210 kPa at 293 K. What will be the tire pressure after driving, if the tire temperature rises to 308 K?

Students measuring the mass of a rock record 6.759 g, 6.786 g, 6.812 g, and 6.779 g. Which other measurement of the block's mass would be most precise? A. 6.702 g B. 6.781 g C. 6.605 g D. 6.858 g