How long does it take a 100.0 g sample of As-81 to decay to 6.25g? How long does it take a180 g sample of Au-198 to decay to 1/8 its original mass?

What is the half-life of a radioactive isotope if a 500 g sample decays to 62.5g in 24.3 hours?

How old is a bone if it presently contains 0.3125 g of C-14, but it was estimated to have originally contained 80.0 g of C-14?

Thallium-208 has a half-life of 3.053 minutes. How long will it take for 120.0 grams to decay to 7.50 grams?

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.