The half-life of chromium-51 is 28 days. If the sample contained 510 grams, how much chromium would remain after 56 days? How much would remain after 1 year? How much was present 168 days ago?

Astudent made the lewis dot diagram of a compound shown. what is the error in the lewis dot diagram? a)an o atom should transfer all of its six electrons to mg because the formula is mgo b) both electrons of mg should be transferred to one o adam because the formula is mgo c) the electrons should be transferred from each o add him to capital mg because mg has fewer electrons d) the number of dots around mg should be four because it has to transfer two electrons to each o

Ibeg i need 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base