Uploaded March 2026 | Updated September 2026, 3 weeks ago
Water is essential to life since every reaction in our bodies takes place in it. But why is water so special? And can we tap into the energy released when a lit splint is added to a mix of hydrogen and water, to create an environmentally friendly solution to our energy problems?
Plants have the ability to reverse this reaction by using the energy from sunlight to release oxygen from water. We are starting to learn how to do the same
We also look at the salts contained in water. Once again we will see the startling difference between a compound and its constituent elements.
Take sodium chloride – aka table salt. Sodium is a soft silvery metal that explodes with water; chlorine a deadly poisonous, choking green gas. Both elements are lethal to us, but after they have met, a dramatic change takes place. The sodium and chloride ions that form are essential components in our bodies. They help generate the electrical impulses that make our brains and nerves work.
About the 2012 CHRISTMAS LECTURES
When medieval alchemists staged spectacular stunts in front of royalty they never revealed the secrets of their mystical potions and fire-breathing creations. Today's chemists can perform equally impressive feats, but they do so to explain and explore the extreme frontiers of our material world.
Watch Peter Wothers, the modern alchemist, as he unpicks the chemistry of the world around us - looking at air, water and earth - three of the original ancient Greek 'elements' that tantalised alchemists for centuries.
---
Chapters 👇
00:00 The Search for the Fountain of Youth 💧
03:40 Is Water Really an Element? (Hydrogen Explosion Demo 🔥)
08:30 Supercooled Water at -3°C (Instant Ice Reaction)
12:45 How Chemical Bonds Release Energy (Hand Warmer Demo)
15:30 Hydrogen Fuel Cells & The Energy of the Future ⚡
20:00 Splitting Water with Electricity (Electrolysis Explained)
25:30 Using Light to Split Water
29:30 What’s Really in Drinking Water?
33:30 Alkali Metals vs Water (Sodium Explosion 💥)
38:00 The Most Reactive Metal: Cesium in Air
41:30 Chlorine, Salt & The Birth of Chemistry
46:00 The Biggest Reaction: Cesium + Fluorine 🔥
50:00 Why the Dead Sea Makes Things Float 🌊
56:30 Half a Kilometre of Hydrogen: The Explosive Finale 💦
---
Join this channel to get access to perks:
youtube.com/channel/UCYeF244yNGuFefuFKqxIAXw/join
Subscribe for regular science videos: bit.ly/RiSubscRibe
The Ri is on Twitter: twitter.com/ri_science
and Facebook: facebook.com/royalinstitution
and TikTok: tiktok.com/@ri_science
Listen to the Ri podcast: podcasters.spotify.com/pod/show/ri-science-podcast
Donate to the RI and help us bring you more lectures: rigb.org/support-us/donate-ri
Our editorial policy: rigb.org/editing-ri-talks-and-moderating-comments
Subscribe for the latest science videos: bit.ly/RiNewsletter
Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.
Water is essential to life since every reaction in our bodies takes place in it. But why is water so special? And can we tap into the energy released when a lit splint is added to a mix of hydrogen and water, to create an environmentally friendly solution to our energy problems?
Plants have the ability to reverse this reaction by using the energy from sunlight to release oxygen from water. We are starting to learn how to do the same
We also look at the salts contained in water. Once again we will see the startling difference between a compound and its constituent elements.
Take sodium chloride – aka table salt. Sodium is a soft silvery metal that explodes with water; chlorine a deadly poisonous, choking green gas. Both elements are lethal to us, but after they have met, a dramatic change takes place. The sodium and chloride ions that form are essential components in our bodies. They help generate the electrical impulses that make our brains and nerves work.
About the 2012 CHRISTMAS LECTURES
When medieval alchemists staged spectacular stunts in front of royalty they never revealed the secrets of their mystical potions and fire-breathing creations. Today's chemists can perform equally impressive feats, but they do so to explain and explore the extreme frontiers of our material world.
Watch Peter Wothers, the modern alchemist, as he unpicks the chemistry of the world around us - looking at air, water and earth - three of the original ancient Greek 'elements' that tantalised alchemists for centuries.
---
Chapters 👇
00:00 The Search for the Fountain of Youth 💧
03:40 Is Water Really an Element? (Hydrogen Explosion Demo 🔥)
08:30 Supercooled Water at -3°C (Instant Ice Reaction)
12:45 How Chemical Bonds Release Energy (Hand Warmer Demo)
15:30 Hydrogen Fuel Cells & The Energy of the Future ⚡
20:00 Splitting Water with Electricity (Electrolysis Explained)
25:30 Using Light to Split Water
29:30 What’s Really in Drinking Water?
33:30 Alkali Metals vs Water (Sodium Explosion 💥)
38:00 The Most Reactive Metal: Cesium in Air
41:30 Chlorine, Salt & The Birth of Chemistry
46:00 The Biggest Reaction: Cesium + Fluorine 🔥
50:00 Why the Dead Sea Makes Things Float 🌊
56:30 Half a Kilometre of Hydrogen: The Explosive Finale 💦
---
Join this channel to get access to perks:
youtube.com/channel/UCYeF244yNGuFefuFKqxIAXw/join
Subscribe for regular science videos: bit.ly/RiSubscRibe
The Ri is on Twitter: twitter.com/ri_science
and Facebook: facebook.com/royalinstitution
and TikTok: tiktok.com/@ri_science
Listen to the Ri podcast: podcasters.spotify.com/pod/show/ri-science-podcast
Donate to the RI and help us bring you more lectures: rigb.org/support-us/donate-ri
Our editorial policy: rigb.org/editing-ri-talks-and-moderating-comments
Subscribe for the latest science videos: bit.ly/RiNewsletter
Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.
