1. Aim: How do we apply logarithms? (Part III)
Do Now: Solve for x:

2. A radioactive substance has a half-life of 3 years
A radioactive substance has a half-life of 3 years. After how long will 20% of the substance remain?

3. The energy, E, in kilocalories per gram molecule, required to transport a substance from the outside of a living cell to the inside is given by:
where C1 is the concentration outside the cell and C2 is the concentration inside the cell.
The concentration of a particular substance inside the cell is six times the concentration outside the cell. How much energy is required to transport the substance from the outside to the inside of the cell?

4. The energy, E, in kilocalories per gram molecule, required to transport a substance from the outside of a living cell to the inside is given by:
where C1 is the concentration outside the cell and C2 is the concentration inside the cell.
The concentration of a particular substance outside the cell is eight times the concentration inside the cell. How much energy is required to transport the substance from the outside to the inside of the cell?