" b) "18" gram "90" centigram into gram."

{:(,"Column I",,"Column II"),("(A)","1 Hectogram","p)",10^(-6)" gram"),("(B)","1 Decagram","q)",10^(2)" gram"),("(C)","1 milli gram","r)","10 gram"),("(D)","1 micro gram","s)",10^(-3)" gram"):}

The half life of radium is 1500 years. After how many years will one gram of pure radium (i) reduce to 1 centigram? (ii) lose one milligram?

A sample of metal weights 210 grams in air 180 grams n water and 120 grams in an unknown liquid then

A sample of metal weights 210 grams in air 180 grams n water and 120 grams in an unknown liquid then

One gram of a radiactive substance takes 50 to lose 1 centigram. Find its half-life period.

One gram of a radiactive substance takes 50 to lose 1 centigram. Find its half-life period.

Compare the number of particles in 18 grams of water and 12 grams of carbon. What conclusion can you draw?

Dheeraj argued that number of molecules in 18 units of water and 18 grams of wateris same .Is it correct or not ?Why ?