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Description
Flashcards by Ahmed Almohammed, updated more than 1 year ago
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Created by Ahmed Almohammed
almost 8 years ago
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| Question | Answer |
| What is the key difference between a physical change and a chemical change? | The key difference between a physical change and a chemical change is that new substances are produced during a chemical change. |
| How can you determine whether a new substance has been produced? | By observing the following-: 1- Permanent colour change 2- Gas is given off 3- Solid precipitates out of a solution 4- Change in temperature |
| Give an example of a physical change that has the ability to produce gas? | Boiling or sublimation.In these cases, a solid or a liquid becomes a gas but no new substances are produced. |
| How can you determine the properties of a substance? | The properties of a substance are determined by the types of atoms it contains and how those atoms are arranged. |
| What happens during a chemical change? | During a chemical change, old substances disappear and new substances form. |
| What is a chemical reaction? | chemical reaction is the process of rearranging atoms to form a new substance. |
| What is the difference between a chemical reaction and a chemical change? | Chemical change is a change that results in a new substance being formed. While chemical reaction is the process of rearranging atoms to form a new substance. Chemical reactions takes place in a chemical change. |
| Identify the reactants and products in the following equations: 1- hydrogen gas+Chlorine gas= Hydrogen chloride gas 2- glucose+oxygen gas= carbon dioxide+ water vapour | Reactants: 1- Hydrogen gas and chlorine gas 2- glucose and oxygen gas Products: 1- Hydrogen chloride gas 2- Carbon dioxide and water vapour. |
| SHOW THE REACTANTS AND THE PRODUCTS >>>>>>>>>>>>>>>> | |
| What is combustion? Give an example | Combustion is the term given to any chemical reaction that involves burning with oxygen to release heat and light , for example, Hydrogen gas+Oxygen gas= water vapour. |
| What is one advantage of a combustion for prehistoric humans? | Combustion allowed prehistoric humans to make light ,cook and keep themselves warm |
| What is photosynthesis? and what is its word equation? | Photosynthesis is a series of chemical reactions that uses sunlight to convert water and carbon dioxide into oxygen gas and glucose. |
| What is respiration? and what is its word equation? | Respiration is the process of obtaining energy from food. |
| Why is respiration such a crucial chemical reaction? | Respiration is a crucial chemical reaction in all living things because it provides the energy for them to live and grow. |
| Why is it that after a long race, athletes are exhausted? | This is because their bodies are starved of oxygen and glucose, so respiration becomes more and more difficult. |
| What is chemical weathering? | Chemical weathering is the gradual breaking down of rocks due to reactions with chemicals in rainwater, hail,sleet and snow |
| list any four physical properties. | |
| List some flammable substances and their use | |
| What is corrosion? and what is the word equation for rust? | Corrosion is a chemical reaction that can happen between metals and the chemicals of their environment. |
| >>>>>Tricky Question<<<<< "When methane gas is burnt in oxygen they produce carbon dioxide and water . Use a word equation to describe this reaction." |
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