“The rate of a chemical reaction depends on the frequency and force of collisions between molecules.”

Each of the chapter headings, with their principles of chemistry, suggest Kate’s maturation. The above epigraph tells the reader to watch as Kate interacts with characters: These interactions lead to her evolution.

“I’m distilling myself in the dark: mixture, substance, compound, element, atom. The ghost is getting closer.”

As Kate runs, she uses chemistry as a metaphor. She feels her complexity breaking down and becomes free of herself. The ghost that hovers, however, reminds her life is not that easy. It reveals a flaw, a piece of irrationality forcing itself into her logical world. These irrationalities will increase as the novel progresses.

“Toby and I are the protons and neutron of our atomic family unit. Dad is the loosely bonded electron, negatively charged, zooming around us in his own little shell.”

After her mother’s death, Kate struggles to keep her family together. The structure of an atom helps her understand their father’s separateness, stemming from his inability to process his wife’s death. Anderson uses a narrative strategy that recurs often—that of literalizing something metaphorical or abstract. Here, it’s the abstract concept of the nuclear family. The image of the family as disparate atomic parts reflects Kate’s STEM understanding of the world.