topic 2 lesson 2 Flashcards
what is an example of a physical change while cooking
kneeding dough, cutting things, and blending
what are some examples of chemical change while cooking
baking, grilling and eating
a change that alters the form or appearance without changing the chemical makeup
physical change
a change in matter that produces one or more new substances
chemical change
when a chemical change occurs when existing bonds ___________ and new bonds _______
break; form
changes in ________ and changes in __________ are both signs that a chemical reaction has occur
energy; properties
what are 3 effects of chemical change
color change, production of a precipitate, and production of a gas.
what is the only way we can be sure that a chemical change has happened
a new substance has occurred
chemical reactions sometimes require a boost of _________ in the form of _______
energy; heat
but other reactions ________ off energy
give
releases more energy than is required to break bonds
Exothermic energy
how is energy released
heat and light
Is exothermic reaction hot or cold
Hot hot
What are some examples of an exothermic reaction
When you put sodium in water
Absorbs energy then produce
Endothermic reaction
Energy is underscore underscore underscore which leaves the surrounding feeling cold
Absorbed
What is an example of an endothermic reaction
Baking soda and vinegar
The minimum amount of energy needed to start a chemical reaction
Activation energy
Chemical reactions do not occur all at the same speed some are very fast like ___________ oh there’s a like the_______ of iron in air are slow
Explosions and oxidization
What other factors are affected when chemical change is done
Surface area temperature concentration Catalyst versus inhibitor
