1 metric tonne=______________milligram.

1 milligram=___

1 gram = _____ milligrams.

1kg=________________tonne.

1 kg =____tonne

1 kg=__________tonne.

1 kg =_____tonne

_____ grams make 20 milligrams.

A radioactive substance has a half-life of 1,700 years. Calculate the time taken for substance to reduce from one gram to one milligram.