A nuclear bomb explodes and releases Barium-140. The half life of Barium-140 is 12.8 days. A test is performed to see how much 140Ba remains 25.6 days later and it is found that there is 15 g of 140Ba remaining. a. How many half lives is this?

b. What % would remain?

c. How many g of Barium-140 was initially present when the bomb exploded?

Astudent made the lewis dot diagram of a compound as shown. mg is written with two dots shown on its top. an o is written on each side of mg. each o has six dots around it. an arrow is shown from one dot on mg toward the vacant space around the o on the right. another arrow is shown from the other dot on mg toward the vacant space around the o on the left. the title of the art is students lewis dot model. what is the error in the lewis dot diagram? an o atom should transfer all its six electrons to mg because the formula is mgo. both electrons of mg should be transferred to one o atom because the formula is mgo. the electrons should be transferred from each o atom to mg because mg has fewer electrons. the number of dots around mg should be four because it has to transfer two electrons to each o.