Bismuth-212 has a half-life of 60.5 minutes. If you start with 128 grams of Bi-212, how much unchanged Bismuth-212 will be left after 7 half-lives?
(include units with your answer *

219 grams of iron (iii) oxide reacts with excess carbon according to the reaction equation shown below. fe2o3 + c → fe + co2 after a scientist performs the chemical reaction they find the actual yield of iron to be 57.4 grams. calculate the percent yield of this chemical reaction.

Mrs. smith ordered a root beer float (vanilla ice cream + root beer). mrs. smith noticed that the three states of matter (solid, liquid, and gas) all existed simultaneously in her root beer float. a. identify each phase of matter in the root beer float. b. describe the particles of all three phases of matter in the root beer float. (how are the particles arranged and moving? ) c. identify one phase change you would see in a root beer float and described what causes this change.

Neils bohr believed that electrons orbited the nucleus in different energy levels, based on strong support from