Q2. (c) A sample of polonium-210 was left for 414 days.
After this time it had a mass of 1.45 x 10-4 g
The half-life of polonium-210 is 138 days.
Calculate the initial mass of the sample.

Which of the following is an example of units for speed

The softest and hardest minerals are: softest hardest

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.