Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
Answer:
it is a transverse wave. Does that help?
Answer:
¾ litters of water was consumed
2.24 litters = 1 mole of water
Therefore ¾÷2.24 moles was consumed
0.33 moles
Answer:
Explanation:
Hello there!
In this case, for this neutralization reaction, it is possible to realize that one the neutralization products is water (pH=7) and the other one is the salt coming up from the cation of the NaOH and the anion of the HI:
Moreover, since the solubility of NaI is large in water, we infer it remains aqueous whereas the water is maintained as liquid:
Which is also balanced as the number of atoms of all the elements is the same at both sides.
Best regards!
Ummmm this one is hard but i guess it would be t?????
