How to tell if a reaction is endothermic or exothermic?

What is the mass of a light bulb

After oil is naturally refined underground, the only way that a viable deposit of hydrocarbons can form is if the oil encounters some kind of

A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica (which is quartz, or SiO2), and iodine.

What is the energy of a photon of blue light with a frequency of 6.7 x 1014 Hz? 6.626 x 10-34 Js 9.9 x 10-49 J 4.4 x 10-19 J 1.0 x 1048 J

Two-thirds of the sulfur dioxide that pollutes the air is produced by

Why does the rate of a reaction generally increase with increased temperature? (Choose all that apply) A. at higher temperatures, molecules are more likely to collide with each other in the correct orientation. B.

What is the wavelength of microwaves of 3.0x109 Hz frequency? c = 3.0x108 m/sec

When DNA is condensing into a chromosome, what protein is it wrapped around?

How does tye transfer of energy affect physical and chemical properties of matter

According to valence bond theory, which kind of orbitals overlap to form the p-cl bonds in pcl5?