Question

Radium has a half-life of 1,620 years. In how many years will a 1 kg sample of radium decay and reduce to 0.125 kg of radium?

1,620 years

3,240 years

4,860 years

6,480 years

Answer 1

PLEASE help me :(

Answer 2

No one will...

Answer 3

okay I will try

Answer 4

this is exponential decay

Answer 5

thank you so much

Answer 6

yes , you have to find the formula for half lifes but i dont understand how to do it

Answer 7

okay tell me the formula YOU HAVE

Answer 8

you divide in half. like if it was 50, it be 25, then 12.5, then 6. 25

Answer 9

so i divided 1 in half three times aand got .125

Answer 10

i dont think thats ir

Answer 11

so that means 3 half lifes so i had to mutiply the 1620 by three i think

Answer 12

and got 4860

Answer 13

hmm, i dont know..

Answer 14

A = 50e ~–0.01t this is 50 grams of a radioactive element that decays at a rate of 1% per year

Answer 15

i dont know. i'm just going to guess. that formulas too complicated

Answer 16

but thank you for the help

Answer 17

okay so
\[0,125 = 1 e ^{1620}\]

Answer 18

yeah i think it is c, im gonna go with that :))

Answer 19

yes c is correct
after 1620 years it weighs 0.5 kg
another ............................o,25 kg
another...............................125 kg

3 * 1620 = 4860

Answer 20

thannk you so much ! :)

Answer 21

definition of half-life is time for the material to decay to a half of its present weight