I think it's The fossil record. The same animal fossil is in Africa and South America. The animal could have not swim across so its the fossil record
"<span>During radioactive decay, atoms break down, releasing, particles or energy" is the one statement about radioactive decay among the following choices given in the question that is true. The correct option is option "b".
"H</span>alf-life" is the term among the following that <span>refers to the time it takes for one-half of the radioactive atoms in a sample of a radioactive element to decay. The correct option is option "d".</span>
The efficiency of the scissor is 200%.
<u>Explanation:</u>
Efficiency is defined as the ratio of output of any instrument or device or machine to the input supplied to it. So the greater the output the greater will be the efficiency of the device.
As here the work done by us on the system is said to be 10 J so this will be equal to the input work done on the system. And the work done by the system i.e., the scissor is 20 J, so this will be the output work.
So, the efficiency is the ratio of output to input as shown below.
Efficiency =
= 200
So, the efficiency of the scissor is 200%.
<span>47 amu is the correct answer</span>