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How do we know a chemical change has happened?
You can tell if something is a chemical changes or a physical change. Examples: Question 1) Ice melting. Answer 1) Physical change because nothing has changed just the shape of the ice. Reversing ice is easy. Question 2) Wick on a candle changes colour from white to black. Answer 2) Chemical change because it changes from clack to white and will be hard to reverse. So if it is a chemical change taking place it hard to convert back or reverse. You can also tell by the change of colour.
What do we call a Chemical change that cannot be undone?
To Answer your question, it can be reversed, but it not so easy. Look at what I found in an article: "Physical changes, like the melting of a solid to a liquid can be reversed easily - just refreeze it. Chemical changes, like the blackening of toast when burnt, are not so easy to reverse." Hope I Helped -- Nick ____________________________________________ Please check out my youtube account, I am going to have some Chemistry experiments and explanations up in a few months! : http:/www.youtube.com/truetechgeek ____________________________________________
What is the difference between a chemical and a physical change?
Physical changes are reversible (reversal is often quite easy).*Chemical changes are not reversible (reversal is often extremely difficult). *The chemical composition of materials is different after a chemical change but the same after a physical change.Chemical change:Bonds have changed; the substances present before the change, are different from those present after the change:A substance reacts to form a new chemical entitysame atoms are used, but different molecules have been created.Examples:The electrolysis of water: the products are two different substances;Combustion of hydrogen in oxygen; forms water and generates heat;The body's combustion of glucose produces carbon dioxide and water;Bread made into toast (partially oxidized bread) is not reversible;Wood burned in a fireplace is not reversible;Burning of the World Trade Center.Physical Change:State, size, shape, or color of a substance is changed basic character-unchanged; Change of physical properties, leaving basic character-unchanged.Examples:Melting of ice: change of state;Bearing gold into a ring;Grinding;Cutting;Folding;Collapse of the World Trade Center* Physical changes aren't always easy to reverse, and chemical changes aren't necessarily impossible to reverse.
How do you know when a chemical change has occurred?
There are many waysif something is burned (not heated or melted but burned)if something changes colorif something spoils or tarnishesif something does not go through a stage of matter such as melting, freezing, evaporating, condensing, sublimatingif something does not just dissolveif something can not be separated in any way
How can irreversible changes change?
I'm not quite sure what you mean here. The term irreversible change is rather meaningless. Some changes are easier to reverse than others, that's all. Melting and freezing water is fairly easy. Melting and freezing iron is more difficult, but not impossible. Some people will tell you chemical changes are irreversible, but that's not true either. Some are easy to reverse, others like burning wood may seem impossible. I can't take carbon dioxide and water and turn them into wood, but plants do it all the time.
What are the 3 examples of chemical change?
A solid is formed in a liquid (precipitate) The change isn't easy to reverse. Heat or light is given off.
Why physical change can easily be reversed but chemical change cannot?
Physical changes are generally easy to reverse because NO ENERGY is produced by the substance.A Chemical change cannot be reversed because ENERGY is produced by the substance forming a new substance.
When an object does not react with hydrogen is that a chemical change or physical change?
Easy, chemical change.
Can appliances have a physical change?
A physical change is something simple, or easy to reverse, like a change of state (Such as ice melting into water). It always occurs after some time on metallic bodies.
Why are boiling and melting examples of physical changes?
You know if it's a chemical chagewhen two or more of the following have happened: 1. a precipitate has formed(bubbles) 2. heat is absorbed or released 3. there is a change in odor 4. there is a change in colour 5. the change is diffiult to reverse 6. starting material is used up 7. a material with new properties is formed A physical change may only be a change in state and the change should be easy to reverse
How do we know a chemical change has happened?
You can tell if something is a chemical changes or a physical change. Examples: Question 1) Ice melting. Answer 1) Physical change because nothing has changed just the shape of the ice. Reversing ice is easy. Question 2) Wick on a candle changes colour from white to black. Answer 2) Chemical change because it changes from clack to white and will be hard to reverse. So if it is a chemical change taking place it hard to convert back or reverse. You can also tell by the change of colour.
Why physical changes can easily be reversed but why chemical cannot?
Physical changes are generally easy to reverse because NO ENERGY is produced by the substance.A Chemical change cannot be reversed because ENERGY is produced by the substance forming a new substance.
What do we call a Chemical change that cannot be undone?
To Answer your question, it can be reversed, but it not so easy. Look at what I found in an article: "Physical changes, like the melting of a solid to a liquid can be reversed easily - just refreeze it. Chemical changes, like the blackening of toast when burnt, are not so easy to reverse." Hope I Helped -- Nick ____________________________________________ Please check out my youtube account, I am going to have some Chemistry experiments and explanations up in a few months! : http:/www.youtube.com/truetechgeek ____________________________________________
Explain Why physical changes can be reversed but chemical changes cannot?
Physical changes are generally easy to reverse because NO ENERGY is produced by the substance.A Chemical change cannot be reversed because ENERGY is produced by the substance forming a new substance.
What are the characteristics of physical changes and chemical changes?
A physical change is either a change of state (solid to liquid, liquid to gas, etc) or a change of shape (squeezing a piece of playdoh or plaster, screwing up a piece of paper). A chemical change involves the production of a new substance, so it involves the rearranging of the atoms in molecules of a substance. A physical change is relatively easy to reverse, a chemical change is hard or impossible to reverse. Signs a chemcial change has taken place include a permanent change of colour, bubbling meaning a gas has been produced, change of temperature, the appearance or disappearance of a material. Examples of chemical change include burning toast, cooking an egg, setting concrete.
Is making cartoons easy?
is making toast a chemical change
Is change easy?
Not always. It depends on how large a change needs to be made and the precise circumstances.
