Brief Summary
This StarTalk episode features Neil deGrasse Tyson, Chuck Nice, and chemist Kate Bieberdorf (Kate the Chemist) answering cosmic queries about chemistry from Patreon supporters. They discuss a range of topics, including the properties and uses of cesium, the science behind the Mentos and Diet Coke explosion, the role of smell in chemistry, the complexities of transition metals, and the potential of AI in chemical research. The conversation also touches on the importance of science communication and the chemist's role in bridging the gap between physics and biology.
- Cesium's unique atomic structure makes it ideal for atomic clocks, defining the duration of a second with incredible precision.
- The Mentos and Diet Coke reaction is caused by nucleation sites on the Mentos attracting carbon dioxide in the soda, leading to a rapid release of pressure.
- Transition metals exhibit varying oxidation states and color changes, making them fascinating for inorganic chemists.
- AI is emerging as a powerful tool in chemistry, capable of analyzing vast amounts of data and predicting new molecular combinations.
- Chemistry plays a crucial role in understanding the world around us, from the formation of solids and liquids to the creation of rocket fuel and everyday items.
Introduction: Kate the Chemist Communicating Science
Neil deGrasse Tyson introduces the episode's focus on chemistry and welcomes Kate Bieberdorf, also known as Kate the Chemist, to StarTalk. Kate is a professor for the public understanding of science at Notre Dame, an author, and the host of "Seeking a Scientist." She will be teaching science communication courses, partnering with the journalism department to train both scientists to be better communicators and journalists to be better scientists. The goal is to bridge the gap between science and the public, as science can be a way of thinking that changes people's lives.
Why Cesium Helps Us Tell Time
Shawn Browning from Hood River, Oregon, asks why cesium has such a violent reaction with oxygen and what its practical uses are. Kate explains that cesium, located in the bottom left corner of the periodic table, has large atoms with a positively charged core and loosely held electrons. Oxygen readily steals these electrons, causing a violent reaction. Cesium-133 is used in atomic clocks, where disturbing the atoms causes them to emit a frequency used to measure time. The consistency of this frequency is so precise that the duration of a second is defined by 9,192,631,770 cycles of cesium atom vibration. This atomic definition of a second is more accurate than the previous definition based on Earth's rotation, which is subject to change.
Why Do Mentos and Diet Coke Explode?
Will from Uklid, Ohio, asks about the history and cause of the Mentos and Diet Coke explosion. Kate explains that the experiment dates back to 1910 with wintergreen Lifesavers, which had a hole in the center that created a geyser effect. In the 1990s, when the Lifesaver company changed the size of the candy, science teachers sought to replicate the effect. Mentos candies have nucleation sites on their surface that attract carbon dioxide in the soda, causing a buildup of pressure and a geyser. Diet Coke is often used because it has high carbonation and doesn't leave a sticky mess like sugary sodas.
Smelling in Chemistry
Andy from Thousand Oaks asks if chemists use their sense of smell in their work, considering the human nose's sensitivity to molecules. Kate confirms that smelling is a tool used in chemistry, but with safety precautions. The proper technique is wafting, gently pushing molecules towards the nose to avoid direct inhalation. The sense of smell can help identify substances and potential hazards. Neil raises the question of whether there are pleasant-smelling substances that are also deadly. He notes that hydrogen sulfide, while having a repulsive odor, can be deadly at levels below detection.
Transition Metals & Electron Configuration
John from Arkansas, a former high school chemistry teacher, asks about the complexities of electron configurations in transition metals and why they are called transition metals. Kate explains that transition metals are named for their ability to transition through different color changes, reflecting their varying oxidation states. Unlike the S and P blocks, transition metals in the D block don't follow typical periodic trends, making them challenging to teach. Certain metals like copper, silver, and gold have electron configurations that deviate from the norm, further complicating the topic.
Making Chemistry Easier to Understand
Mihir asks about the effectiveness of books that simplify complex topics like quantum physics for babies and whether graduate-level science should be introduced at the elementary level. Kate discusses her children's books, which aim to share science with the general public in a fun and accessible way. She believes that experiments can be lasting and trigger curiosity, and that educators sometimes overvalue lesson plans relative to inspiration. Exposing children to scientific vocabulary early on can help them develop a general understanding of concepts before they encounter them in formal science classes.
The Hunt for “The Island of Stability”
Hunter from Columbus, Georgia, asks about the island of stability and the properties of atoms within it. Kate explains the band of stability, which relates to the ratio of neutrons to protons that makes an atom most stable. Neil elaborates on the island of stability, a theoretical region beyond the currently known elements where heavier, more stable elements may exist. These elements would have unique properties and potentially revolutionize chemistry.
Chemistry in Space
Jessica from Toronto and Dubai asks how chemical reactions, especially combustion, change in space where there is no oxygen and minimal gravity. Kate explains that in zero gravity, reactions behave like gas-phase reactions, allowing for experiments that are impossible on Earth. Neil adds that combustion in zero G is limited by the availability of oxygen, as heated gases don't rise to bring in fresh oxygen. Kate and Neil discuss the combustion of liquid hydrogen and liquid oxygen in rockets, which produces water as a clean exhaust. They also ponder the possibility of quantum entanglement between molecules.
An Experiment to Do with Your Family
Alyssa from Rocket City Hunts Alabama asks for a kid-friendly experiment for her daughters. Kate suggests the exploding paint can experiment, which involves mixing baking soda and vinegar in a sealed paint can to create carbon dioxide and cause the lid to pop off. She emphasizes the importance of safety goggles and adult supervision.
Chemistry’s Future with AI
James from Denmark asks about the most promising developments in applied chemistry today. Kate highlights the merging of chemistry with AI, citing an example where Microsoft AI suggested a replacement for lithium in lithium-ion batteries. AI can analyze vast amounts of data and predict new molecular combinations, accelerating research. Neil mentions the CRC Handbook of Chemistry and Physics, a comprehensive compilation of scientific data that AI could ingest to generate new chemical insights.
A Cosmic Perspective
Neil reflects on the interconnectedness of physics, chemistry, and biology, emphasizing the crucial role of chemistry in understanding the world around us. He highlights the chemist's contributions to civilization, from creating new materials to developing life-saving technologies. Kate promotes her podcast, "Seeking a Scientist," where she interviews other scientists and brings a science communication perspective to their expertise.
