(21) A radio-active substance has a half life of six months. Three-fourth of the substance will decay in ______. (a) Six months (b) Ten months (c) Twelve Months (d) Twenty four mon
option C . Half lifestyles of any radioactive substance is the quantity of time required for the decay of substance to the 1/2 of of its preliminary value. After one 1/2 of lifestyles, we can have ½ of the substance remaining. After any other 1/2 of lifestyles, we are able to have ¼ of the substance remaining. It manner 3/4th of the substance will decay after 1/2 of lives. 1 Half lifestyles = 6 months 2 Half lives = 12 months
