The nucleus of lithium contains three protons and three neutrons. When two electrons are removed from the neu-
tral lithium atom, the remaining electron has an average
distance from the nucleus of 0.018 nm. What is the force
between the electron and the nucleus at this separation?

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)