Calculate the effective radiation dosage in sieverts for a 57 57 ‑kg person who is exposed to 4.2 × 10 9 4.2×109 particles of alpha radiation. Only 81 % 81% of the radiation is absorbed. Assume each alpha particle has an energy of 6.1 × 10 − 13 6.1×10−13 J and that the RBE of the alpha particles is 15 15 . Note that RBE is sometimes called the quality factor ( Q Q ).

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.

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j

How much energy must a refrigerator absorb from 225 g of water so that the temperature of the water will drop from 35°c to 5°c