Why do some liquids burn and others don’t? Some liquids require less energy to get the chemical reaction over the activation energy barrier. What is fire? Fire is the process of combustion and is a chemical reaction. Fire needs three things to happen: a fuel source, heat, and oxygen. If you remove one of these, […]
#325 Why do some liquids burn and others don’t? Read More »
How do chemotherapy and radiotherapy work? Chemotherapy works by damaging the DNA inside the nucleus of the cancer cells and stopping them dividing. Radiotherapy works by targeting the cancer directly and damaging its DNA. How does cancer form? As our cells age, they die and new cells replace them. Some cells are replaced more quickly
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How does a pressure cooker work? By using high pressure to raise the boiling point of the water. Pressure cookers were invented in 1679 by a French physicist. He was trying to find a way to cook food faster. Cast iron pressure cookers were made in Germany in 1864. Pressure cookers improved through the early
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How does a refrigerator cool food? By transferring the heat from inside the refrigerator to outside using evaporation. Fresh foods have to be kept cool to make them last longer. As soon as they are opened, or cut, bacteria start to decompose them. When foods decompose, they taste bad, but some bacteria can produce toxins
#320 How does a refrigerator cool food? Read More »
Why does metal spark in a microwave oven? The microwave charges one side of the metal positively and one side negatively. This charge can ionize the air, making sparks. First, we need to look at what microwaves are. A microwave is a type of electromagnetic radiation. Electromagnetic radiation is energy that moves in waves and
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How does a steam engine work? By taking the energy contained in coal and making heat. Then using the heat to turn water into steam and using the steam to push and pull a piston. The steam engine was the invention that helped push the Industrial Revolution. However, the knowledge of steam power has been
#316 How does a steam engine work? Read More »
How tall could a skyscraper be? Theoretically 69.1 km tall, but practically, about 2 km. The tallest building in the world at the moment is the Burj Khalifa. It is 830 meters tall. For over 3800 years, the tallest building in the world was the Great Pyramid at Giza. It was 147 meters tall when
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How does an electroencephalogram work? By measuring electrical activity in different parts of the brain using electrodes on the scalp. EEGs are used to diagnose disorders with the electrical activity in the brain. These can be epilepsy, sleep disorders, anesthesia, coma, and even brain death. It is most commonly used for diagnosing epilepsy, which is
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Is nuclear waste dangerous? It is if it isn’t handled properly. This was interesting to research. All of the sites I looked at that were run by nuclear organizations said, “no, no, of course not,” while the sites I looked at from other sources said, “possibly.” When we think about nuclear waste, we think about
#309 Is nuclear waste dangerous? Read More »
How does an AED work? It has sensors to detect the rhythm of the heart and it has a powerful battery to deliver a shock to correct the heart. AED stands for Automatic External Defibrillator. It is a defibrillator that is automatic. So, let’s start by finding out what a defibrillator is. A defibrillator is
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