Problem: The ionization energies of the representative elements generally decrease from top to bottom within a group. This trend is explained by the increase in size of the atoms within a group. The valence electron that is being removed is further from the nucleus in the case of a larger atom. The attractive force between the valence electron and the nucleus weakens as the distance between them increases and as the shielding effect increases, resulting in a lower ionization energy for the larger atoms within a group. Although the nucl Rob is learning about ionization. He looks at a specific group of elements from top to bottom to figure out thier ionization energy. Given the top element and the bottom element in the group Rob looks at, which has a lower ionization energy?

A: bottom element

Problem: 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. Two high school buddies, Dan and Bob, had very different lifestyles 30 years later. Dan made only healthy lifestyle choices, was vegan. Bob ate meat, cheese and didn't care about his health and didn't protect himself. Which man smoked tobacco, Dan or Bob?

A: Bob

Problem: Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions primarily from use of fossil fuels and deforestation have rapidly increased its concentration in the atmosphere, leading to global warming. Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid. Ben and Andy researched significant greenhouse gasses in Earth's atmosphere. Andy researched more about carbon dioxide, while Ben researched methane gas. Which researcher studied less about ocean acidification?

A: Ben

Problem: A mycorrhiza (Greek for "fungus roots") is a symbiotic association between a fungus and the roots of a plant. In a mycorrhizal association, the fungus may colonize the roots of a host plant by either growing directly into the root cells, or by growing around the root cells. This association provides the fungus with relatively constant and direct access to glucose, which the plant produces by photosynthesis. The mycelia of the fungi increase the surface area of the plant's root system. The larger surface area improves water and mineral nutrient absorption from the soil. Fox and Ken were two aspiring horticulturists. Ken studied more about plant pollination, while Fox studied about mycorrhizal fungi. Which friend read less about fungi growing around the root cells?

A:
Ken