Physical or Chemical Properties
A ___________________is the characteristics of a substance that can be observed without changing the identity of the substance.
physical properties
If you do not know what a substance is, exploring the ___________________ of the substance can help with identifying the substance. These are characteristics of a substance that don’t change.
properties
A _______________________ alters a substance’s shape or appearance without changing its chemical composition. No new substances are formed, and the change can often be reversed.
physical change
In this example, 2 Na + Cl2 → 2 NaCl. The arrow represents a
chemical reaction
___________________are the smallest bits of ordinary matter. They are also referred to as the building blocks of matter.
Atoms
A_______________________is a characteristic that describes a substance's ability to undergo a chemical reaction and change into a new substance. These properties cannot be observed without changing the identity of the substance.
chemical properties
We created models using Dots (candy) and toothpicks. -Explain what the Dots (candy) represented.
-Explain what the toothpicks represented.
-Explain what the Dots (candy) and toothpicks together represented.
We made 3D models using Dots (candy) and toothpicks.
The Dots (candy) represented atoms.
The toothpicks represented chemical bonds, which hold atoms together.
The Dots (candy) and toothpicks together represented molecules and compounds.
A _______________________ is a process where a substance transforms into one or more new substances with different properties. These changes are difficult or impossible to reverse. Bonds between atoms and molecules are broken and new ones are formed.
chemical change
In this example, 2 Na + Cl2 → 2 NaCl.
2 Na + Cl2 is the _______________________ side.
reactant
Phase changes, such as melting, boiling, etc. are all ____________________ changes.
physical
_______________________ is a property related to a material’s ability to ignite or catch fire. We explored this property when trying to determine what gas was produced by the bath bomb.
Flammability
Define physical and chemical changes and provide an example of each.
-A physical change alters a substance’s shape or appearance without changing its chemical composition. No new substances are formed, and the change can often be reversed.
-An example of a physical change is slicing an apple. The identity of the substance remained the same.
-A chemical change is a process where a substance transforms into one or more new substances with different properties. These changes are difficult or impossible to reverse. Bonds between atoms and molecules are broken and new ones are formed.
-An example of a chemical change is an apple turning brown. There is a change in color, which is evidence of a chemical reaction
Breaking glass is an example of a _________________.
physical change
In this example, 2 Na + Cl2 → 2 NaCl.
2 NaCl is the _______________________ side.
product
After a chemical reaction, the mass is the _______________________ (same or different).
same
___________________ is a property that measures how much "stuff" (mass) is packed into a certain amount of space (volume). Often we compare this to water and whether a material would sink or float in water.
Density
When we did the activity with Legos, what did the Legos represent? What did the Legos and what they represented have in common?
The Legos represented atoms. Legos and atoms are building blocks. Atoms are the smallest bits of ordinary matter and are the building blocks of matter.
When the bath bomb was put in water, it fizzed. This was an example of a ________________.
chemical change
When a chemical reaction occurs the number of ________________ is the ________________ on both sides of the reaction.
atoms; same
Of the listed properties, which is not a physical change.
-density
-luster
-flammability
-conductivity
flammability