Chalter 3 Test 3.3 Flashcards
Physical change
A substance changes in form but not in its chemical composition. The appearance may change but but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have not been made. Has to do with energy changes
Example of : physical change
Candy/chocolate melting- it may melt into a liquid, but it’s still the same thing just its appearance has changed.
Also Dissolving is another.
Ripping,cutting, grinding , tearing is all physical changes.
Chemical change
New chemical bonds are formed while others are broken, Produces new substances with new properties. Is also accompanied by energy changes. New bond are formed while others are broken. Start with a substance that will react, new substance that produces is called a product. Evidence: colour change, heat, light, sound produced or consumed, bubble gas forms, precipitate may form.
Difference between : CHEMICAL AND PHYSICAL CHANGES
There are several differences between a physical and chemical change in matter or substances. A physical change in a substance doesn’t change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. Something new and something with just a difference appearance
Reactants
Substance that react in a chemical change. Reactants are substances present in a chemical reaction that are consumed during the reaction to make products
Products
The compound that is formed when a reaction goes to completion . It’s what happens after a consumption of reactants. It happened when feats gs pass through a high energy state.
EXAMPLE : chemical change
Rust, burning of wood, cooking an egg, baking a cake
Endothermic
One of 2 types of energy involved with chemical and physical changes, endothermic means being absorbed, so if energy is being absorbed like cooking an egg melting ice, baking bread
Exothermic
This is if energy is being released , water freeIng, iron rusting, fireworks,
