The maximum number of electrons found in any energy level (shell at any point in time is calculated by the formula

Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons.

1. What does the x-axis represent in this situation?

The x-axis represents time.

2. What does the y-axis represent?

The y-axis represents distance.

3. During which parts of the graph does Arthur's distance from home decrease?

Sections 2 and 4.

4. When is Arthur waiting for bagels? Explain how you know.

Section 3. The flat areas represent times when Arthur is not moving. We know that the first flat area shows Arthur reading his newspaper, and the third is when he reaches home; so the second flat area represents the time in which Arthur is waiting for bagels.

5. If Arthur's pace had not been constant after leaving the bagel shop, which part of the graph

would change? Explain how that part of the graph would change.

The part of the graph that would change is part 4. If his pace was not constant, section 4 would not be uniform, and would have many abnormalities. Essentially, Arthur would be randomly speeding up and slowing down.

6. If Arthur had spent less time reading his newspaper, which part of the graph would change? How would that part change?

If Arthur had spent less time reading his newspaper, the whole graph would change. Section one would be shorter, and the entire line would also be shorter. The distance on the graph from the beginning of section 1 to the end of section 5 would be reduced.