user: Question: Background: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy.  Paragraph: Seattle produces a large amount of their electricity by burning fossil fuels due to the large presence of natural coal in the state. Montreal, on the other hand, produces a large percentage of their electricity through the use of nuclear fission thanks to the large number of nuclear power pants in that state.  Given the paragraph above, please answer correctly the following question: Which city, Seattle or Montreal, will produce more air pollution?
Answer: Seattle

Question: Background: However, when going across a period from left to right, the atomic radius actually tends to decrease. Why is this so? Each successive electron is going into the same principal energy level as the previous one, so the total amount of occupied space does not really go up significantly. Additionally, because protons are also added to the nucleus as you go across the row, the pull of the positively charged nucleus on the negatively charged electrons increases. This tighter pull leads to a slight decrease in atomic radius. As a result, the atomic radii of the elements exhibit a periodic trend, gradually tends to downward, but with a sharp spike up whenever electrons are added to a new principal energy level ( Figure below ).  Paragraph: There are two elements, Zaxon and Barton. Zaxon is an element that is further left on the period, and Barton is on the right of the period.  Given the paragraph above, please answer correctly the following question: Which element will have a larger atomic radius?
Answer: Zaxon

Question: Background: Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens , which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure below ). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesn’t matter whether the radiation comes from tanning lamps or the sun.  Paragraph: Justin and Robert are brothers who both work in construction in the summers. Due to their work, they both often spend a lot of time outside with the sun shining down on them for several hours a day for a few months at a time. Justin always makes sure to apply sunscreen frequently when he works, while Robert never applies sunscreen.  Given the paragraph above, please answer correctly the following question: Who has a lower risk of getting skin cancer?
Answer:

assistant: Justin