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Some reactions are called endothermic ("into-energy") meaning that they require excess energy in order to react. This will cause the reaction to feel cold. Other rections are exothermic ("out-energy"), meaning that they give off heat.
Reactions only occur when the environment around them contains enough energy (e.g. lighting a fire, cooking) to push them over what's called a reaction threshold. This is their "activation energy". It is different for every reaction. Many reactions that we call spontaneous are actually just reactions that have reached that threshold under normal conditions, which is 1 atmosphere of pressure and 75 degrees Fahrenheit. This is also called Standard Temperature and Pressure, or STP. If you lower the temperature or pressure, these reactions might stop or not occur at all. Other reactions occur at very low temperatures and pressures, and others occur at much higher ones. Every reaction has a temperature-pressure curve which shows under which conditions the reaction will occur.
Lastly, there is an effect called catalysis. This uses a material, often a metal, to artifically lower the reaction energy for the components. This happens by bringing the reactants together on the surface of the metal, where they naturally combine. Using catalysis means having to put less energy into a system for the reaction to occur. Catalysts are reusable and do not become part of the products. A good example of catalytics occurs in your own body: enzymes are special strings of proteins which catalyze certain reactions, such as breaking down food or transferring nutrients into and waste out of cells. In some cases, enzymes cause reactions in your body which would otherwise go so slowly that there's no way you could stay alive!
What else can I help you with?
What do chemical reactions that absorb energy need to occur?
Chemical reactions that absorb energy need an input of energy in the form of heat, light, or electricity to overcome the activation energy barrier and initiate the reaction. This added energy allows the reactant molecules to surpass their energy threshold and transition into a higher-energy state, leading to the formation of products.
Chemical reactions that energy often occur spontaneously?
Chemical reactions that release energy often occur spontaneously because they lead to a decrease in the overall energy of the system. Exothermic reactions, which release heat energy, are usually spontaneous because they increase the randomness or entropy of the system, following the second law of thermodynamics. This decrease in energy and increase in entropy drive the reaction to proceed without the need for external energy input.
How does enzymes speed up chemical reactions in your body?
Reactions in the body need a certain amount of energy, called activation energy. Most reactions don't take place because this activation energy is too high. The enzyme bonds to the molecule which diminguishes the activation energy, so the reaction can take place. These enzymes de-bond from the new formed molecule afterwards.
What is the basis of all chemical reactions?
Chemical reactions are based on the interactions between atoms and molecules, specifically the rearrangement of chemical bonds. These interactions involve breaking existing bonds and forming new ones, resulting in the transformation of reactants into products with different chemical properties.
What are two chemical reactions that require energy in order to occur?
Photosynthesis: The reaction where carbon dioxide and water are converted into glucose and oxygen by plants using sunlight. Endothermic reactions: Reactions that involve the absorption of heat energy from the surroundings, such as the decomposition of calcium carbonate to form calcium oxide and carbon dioxide.
Do all chemical reactions need energy to start off?
yes they all need more or less start up energy
What do chemical reactions in living organisms need to start?
Chemical reactions in living organisms require a source of energy to start. This energy is typically obtained from molecules such as ATP. Additionally, enzymes play a critical role in catalyzing these reactions by lowering the activation energy required for the reaction to occur.
Do all chemical reactions need heat to start them off?
No, not all chemical reactions require heat to start. Some reactions can occur at room temperature or even at low temperatures. Heat is often used to speed up reactions or provide enough energy to overcome the activation energy barrier.
Do chemical reactions need heat to start them off?
Endothermic reactions need heat.
Do all chemical reactions need heat to start them?
no
What are some things that need chemical energy?
Candle and all Chemical reactions
What is the role of energy in chemical reations?
All chemical reactions need a certain amount of activation energy to get started.
What are some things that need energy?
Candle and all Chemical reactions
What do chemical reactions that absorb energy need to occur?
Chemical reactions that absorb energy need an input of energy in the form of heat, light, or electricity to overcome the activation energy barrier and initiate the reaction. This added energy allows the reactant molecules to surpass their energy threshold and transition into a higher-energy state, leading to the formation of products.
What does the amount of energy affect during a chemical reaction?
A chemical reaction need an activation energy to start.
What are light independent and dependent reactions?
Light dependent reactions are reactions the capture light energy and convert it into chemical energy(ATP). It occur in the chloroplast of plant cells Light independent reactions are reactions capture energy and use it to produce food . It does not need sunlight
Have you ever wondered how energy participates in chemical reactions?
I wonder about a lot of things, yes.
