A radioactive tracer has a half life of 2 hours. How much of a 2500 g sample will be available after 24 hours?

A) 2.44 g

B) 1.22 g

C) 0.610 g

D) 0.31 g

When lead acts as a poison, it can do so by either replacing another ion (such as zinc) in the active site of an enzyme or reacting with cysteine side chains to form covalent bonds. which of these is irreversible and why?

7. What is differential heating? Where is the sun's incoming solar radiation the strongest? Where is it the least?

The names of muscles often indicate the action of the muscle. what does the term levator mean?

Water is warmed by the sun and

How long has carbon been underground?

The map shows the distribution of wild boars in the United States. Wild boars are an invasive species to the United States. A map of the United notes showing the distribution of wild boars in dark orange.

Deep ocean currents are driven by differences in O temperature, pressure, and pH density, salinity, and temperature the alignment of the Sun, moon, and Earth evaporation, condensation, and precipitation

There are many different types of objects in the solar system. Which type of object is the Sun? A. star B. outer planet C. asteroid D. inner planet

Cell Division 1. Why do we have two types of cell division? (mitosis and meiosis) Explain your answer

Under what circumstances would an early reading be allowable