Answer: half life
Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

t= time required
k= disintegration constant
x= amount of substance left after time t
a= initial amount of substance
when one half of the sample is decayed, one half of the sample remains and t can be represented as 
at
, 


B, the Internet.
If Caitlin told Teddy that the largest diamond was found YESTERDAY then it wouldn't be in last month's science magazine. It also wouldn't be able to be in an encyclopedia at the library because there wouldn't have been any time to write, publish, and for the library to get the encyclopedia in one day. Caitlin's parents may not know about Caitlin's claim or about the diamond in the first place. The Internet would likely have an article about the news-breaking diamond as soon as possible.
Its magnifying power is: 4X 5X 9X 20X. A 4-inch, f/5 telescope has a 1-inch eyepiece focal. Its magnifying power is 9x. This answer has been confirmed as correct and helpful.
Answer:An oxygen atom usually has 8 protons, 8 neutrons, and 8 electrons. Looking at the periodic table, oxygen has atomic number 8 and atomic weight 15.999.
Explanation: