Curated Video
Indicator
A substance that provides a visual indication of the pH of a test material. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science Glossary Films...
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Acid
A compound which dissolves in water to form a solution with a pH of less than 7. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science Glossary...
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Base (chemistry)
A substance that reacts with an acid to form a salt and water. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science Glossary Films reinforce...
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pH
The pH scale measures the acidity or alkalinity of a solution. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science Glossary Films reinforce...
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Factpack: pH Scale
Explore the pH scale, and discover whether a solution is acidic, alkaline or neutral. Chemistry - Reactions - Learning Points. A Twig FactPack Film. Open a discussion on what has been already learnt in a topic, or use to grab attention...
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Acids and Alkalis: Part 2
Alkalis and acids can be neutralised to great and varied effect. For example, it is neutralisation reactions that help us breathe underwater or cure indigestion. Chemistry - Reactions - Learning Points. A neutral solution is pH 7 Sodium...
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Crystals in Caves
Discover the chemical processes occurring deep within the Earth that create beautiful crystal structures in caves. Chemistry - Reactions - Learning Points. Caves are a result of rainwater slowly carving away rock. Carbonic acid forms in...
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Limestone: Features
Easily eroded by water, limestone's composition means it makes up spectacular sights all over the world. Learn about some of the surface and underground features of this rock type. Earth Science - Geology - Learning Points. Limestone is...
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Healthy Teeth - Dental Care Tips
Your teeth are exceptionally strong, but without the proper care they can be easily damaged. Learn how a few simple steps can help avoid tooth decay. Biology - Healthy Living - Learning Points. A build-up of plaque on your teeth can lead...
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Acids and Alkalis: Part 1
The properties of strong acids and alkalis can be extremely harmful. Where do we find them, and how can we tell how acidic or alkaline a substance is? Chemistry - Reactions - Learning Points. Bases neutralise acids, and if a base...
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Reactivity Series: Comparing the Reactivity of Group 1 and Group 2 Metals
We compare the reactivity of Group 1 and Group 2 metals. We add sodium and then potassium to water. We observe the reactions. Next we add magnesium and then calcium to hydrochloric acid and observe the reactions. The results let us put...
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Bouncing Eggs
We use vinegar to remove the shells from eggs without breaking them. Two eggs are placed in a beaker of vinegar, but one is half coated with clear nail polish. The exposed shells dissolve over time and the eggs swell as more water moves...
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Stomach Acid and Antacid
We use the enzyme pepsin and hydrochloric acid to simulate the conditions within the stomach in two boiling tubes. Cooked egg whites are ground and added to two boiling tubes of hydrochloric acid, but one is mixed with a crushed antacid...
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Citrus Fruit Battery
We use lemons and strips of zinc and copper to make a battery. First, strips of copper and zinc are added to one lemon and they are connected across a voltmeter. This is repeated, this time with more lemons and metal plates, until a...
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Acidification of Water
We use a drinking straw, some water and universal indicator to show that breathing out creates acid. Universal indicator is added to the water to show its pH value. When we blow into the water the indicator changes colour showing that...
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Agar Cube Diffusion
We use coloured agar cubes to see how different shapes change the rate of diffusion. The cubes are made using sodium hydroxide and phenolphthalein indicator to give them a pink colour. When these are added to hydrochloric acid, the...
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Inflating Glove
We inflate a rubber glove using the gas produced during a neutralisation reaction. Bicarbonate of soda is added to vinegar in a beaker covered by a rubber glove and it expands. The gas is used to extinguish a flame, showing that it is...
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Neutral
In between two extremes, neither one thing nor another. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science Glossary Films reinforce abstract...
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Salt
In chemistry, an ionic compound containing positive metal ions and negative non-metal ions. A Twig Science Glossary Film. Key scientific terms defined in just 60 seconds using stunning images and concise textual definitions. Twig Science...
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The intestines
Case study of the role of the intestines in digestion. Life processes - Body systems - The digestive system Learning Points The intestine is divided into the large and small intestine. Nutrients from food are absorbed into the...
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Healthy Teeth - Tooth Care
Top tips for keeping your teeth healthy. Life processes - Humans and other animals - Teeth Learning Points Bacteria in the mouth produce plaque. Acid produced by plaque attacks the enamel on teeth. Brushing teeth twice a day helps...
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The mystery of the narwhal tooth
The narwhal is known as the 'unicorn of the ocean' ... but what exactly is that horn for? Life processes - Humans and other animals - Teeth Learning Points The narwhal's unusual tooth is a sensory organ. A Twig Context Film. Reinforce...
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Function of teeth
Why do we have teeth and how are they different to those of other animals? Life processes - Humans and other animals - Teeth Learning Points Different teeth serve different functions. Carnivores, omnivores and herbivores have different...
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Symmetry and Optical Activity: Do Your Molecules Have It?
Symmetry and optical activity are intricately linked in organic molecules. A molecule is optically active if it can rotate the plane of polarized light. Optical activity arises from the molecule’s lack of symmetry—specifically, its...