If you added a spoonful of salt to a beaker of water and stirred until the salt dissolved, would the result be a pure substance or mixture? What specific type?
Mixture; homogenous
100
Which of the following is not a sign of a chemical change? change of odor; change of color; evaporation of water; release of gas
evaporation of water; (evaporation is change of state from liquid to gas which is a physical change)
100
A molecule of water is made from _?_ (chemically/physically) combining 2 hydrogen atoms and one oxygen atom. How many atoms are in NaCl? Fe2O3?
chemically; 2; 5
100
Name 4 physical properties of gold:
shiny, gold color, good conductor of heat/electricity; melting point; boiling point; solid; malleable; high density;
100
What are the 2 main categories of matter? Which one can be further classified into elements and compounds? Which one can be further classified into homogenous and heterogenous?
Mixtures and Pure Substances; pure substances; mixtures
200
Elements and compounds are both pure substances. Which of these is found on the periodic table? Which consists of only 1 type of atom? Which can be represented by a chemical formula? Sodium is an example of a(n) _?_; while sodium chloride is an example of a(n): _?_
Elements; elements; compounds; element; compound
200
If a new substance forms, a _?_ reaction has occurred. Baking a cake or burning are good examples because the cake ingredients/batter has different properties than a baked cake and a burned log has different properties than an unburned log.
chemical
200
Mixtures are _?_ combined. The components of a mixture _?_ (do/do not) retain their own identities and _?_ (can/cannot) be separated by physical means.
Physically; do; can
200
Explain why changes of state are physical changes
changing the state (solid, liquid, gas) does not change the identity of the substance. Ex: ice and steam are still water
200
A group of atoms that act as a unit is called a(n) _?_; are they pure substances?
molecule; yes
300
The science of what matter is made of and how it changes is called _?_. All matter has these three properties: made of atoms, _?_ and _?_
chemistry; has mass; takes up space
300
The unit for mass is the _?_, while the unit for volume is the _?_. This means that the unit for density is the combined unit _?_
gram (g), milliliter (mL) or cubic centimeter; g/mL or g/cm3
300
A substance that cannot be broken down into simpler substances is a(n) _?_. Pure substances always have a _?_ (fixed/varied) composition.
element; fixed
300
The density of water is _?_ g/mL. Ice floats because it is _?_ dense than water.
1.00 g/mL; less
300
The 2 chemical properties are: __?__ and _?_. If a substance has one (or both) of these, the original substance will _?_ (retain its properties/change into something with new properties)
reactivity and flammability; change into something with new properties
400
Sound is not matter because it has neither _?_ nor _?_.
mass; volume;
400
If you were to graph the density of a substance, the _?_ would be graphed on the y-axis because it depends on _?_ which is on the x-axis.
mass; volume
400
When two are more substances are blended together, a _?_ results. If the substances are immiscible, then layers will form. In this case, the combined substances would be classified as a _?_ _?_
mixtures; heterogeneous mixture
400
Which of the following TWO are examples of a chemical change: ice melting; pounding gold into a coin; paint fading; a puddle evaporating; digesting food
paint fading; digesting food
400
List 4 clues that suggest a chemical change is taking place:
1) change of color; 2) change of odor; 3) emission of Energy in the form of heat/light/sound; 4) release of gas (bubbles, fizzing)