After three times the particle half-life of radioactive particle, 1/4 of the particle will remain un-decayed. O True O False

False

Explanation:

Let the initial amount is No.

Let t be the half life.

Half life is the time in which the initial amount of the substance becomes half and the remaining amount in teh sample is also half.

After one half life, the remaining amount is No / 2

After two half lives, the remaining amount is No / 4

After three half lives, the remaining amount is No / 8.

So, the statement is false.