True or false: 1) a solution is made up of at least two substances 2) a solution must contain at least one liquid 3) the solvent in a solution may be solid

Which element forms an ionic bond with flourine? 1) fluorine 2) carbon 3) potassium 4) oxygen

All cells are made of four types of acids, lipids, proteins, and carbohydrates.

If you chip a tooth, most likely you will go to the dentist to have the missing material filled in. currently the material used to fill in teeth is a polymer that is flexible when put in, yet is hardened to the strength of a tooth after irradiation with blue light at a wavelength of 461 nm. what is the energy in joules for a photon of light at this wavelength?