CHEM 141 Unit 1 CORRECT 100%
What is Chemistry? - ANSWERthe study of matter; its properties and the changes it
undergoes
What is a substance? - ANSWERmatter that has a composition that does not vary from
sample to sample
What are the two types of substances? - ANSWERElements and Compounds
What is an element? - ANSWERA substance which can not be decomposed to simpler
substances
What is a compound? - ANSWERa substance which can be decomposed to simpler
substances because it is made up of more than one element
Is wood a pure substance? - ANSWERNo
What are atoms? - ANSWERthe building blocks of chemical matter
Hydrogen, Oxygen, and water are all composed of molecules. What is it about a
molecule of water that makes it a compound, whereas hydrogen and oxygen are
elements? - ANSWERthe water molecule contains atoms of two different elements
When water is split into hydrogen and oxygen gases, the resulting volume of oxygen is
smaller than that of hydrogen. Why? - ANSWEREach H2O molecule contains one
oxygen atom and two hydrogen atoms, so twice as many H2 molecules are produced
compared to O2
What is a mixture? - ANSWERA substance that consist of different kinds of molecules
What are the two types of mixtures? - ANSWERHeterogeneous and Homogeneous
What is a heterogeneous mixture? - ANSWERa mixture varying composition throughout
a sample
What is a homogeneous mixture? - ANSWERa mixture that has the same composition
throughout
What are physical properties? - ANSWERCharacteristics that can be observed without
changing the substance into another substance
What are some examples of physical properties? - ANSWERcolor, odor, density,
melting and boiling points, hardness, etc.
, What are chemical properties? - ANSWERCharacteristics that can be observed only
when the substance is changed into another substance
What are some examples of chemical properties? - ANSWERflammability and other
types of reactivity, etc.
What are intensive properties? - ANSWERProperties that are independent of the
amount of the substance present
What are some examples of intensive properties? - ANSWERdensity, color,
temperature, boiling point, etc.
What are extensive properties? - ANSWERproperties that are proportional to the
amount of the substance present
What are some examples of extensive properties? - ANSWERmass, volume, energy,
etc.
When we say that lead is a "heavier" (more dense) metal than aluminum, are we talking
about an extensive or intensive property? - ANSWERIntensive
What is physical change? - ANSWERa change that does not change the elemental
composition
What are some examples of physical changes? - ANSWERchanges of state (gas, liquid,
solid), temperature, volume, etc.
What are chemical changes? - ANSWERa change that results in a new substance
What are some examples of chemical changes? - ANSWERCombustion, oxidation,
decomposition, etc.
Plants make sugar from carbon dioxide and water. Is this change physical or chemical?
- ANSWERChemical
Water vapor in the air forms frost. Is this a physical or chemical change? -
ANSWERPhysical
What are the three main states of matter? - ANSWERSolid, Liquid, Gas
What is potential energy? - ANSWERthe energy of the object's interaction with other
objects
What does potential energy depend on? - ANSWERthe object's relative position with
respect to other objects
What is Chemistry? - ANSWERthe study of matter; its properties and the changes it
undergoes
What is a substance? - ANSWERmatter that has a composition that does not vary from
sample to sample
What are the two types of substances? - ANSWERElements and Compounds
What is an element? - ANSWERA substance which can not be decomposed to simpler
substances
What is a compound? - ANSWERa substance which can be decomposed to simpler
substances because it is made up of more than one element
Is wood a pure substance? - ANSWERNo
What are atoms? - ANSWERthe building blocks of chemical matter
Hydrogen, Oxygen, and water are all composed of molecules. What is it about a
molecule of water that makes it a compound, whereas hydrogen and oxygen are
elements? - ANSWERthe water molecule contains atoms of two different elements
When water is split into hydrogen and oxygen gases, the resulting volume of oxygen is
smaller than that of hydrogen. Why? - ANSWEREach H2O molecule contains one
oxygen atom and two hydrogen atoms, so twice as many H2 molecules are produced
compared to O2
What is a mixture? - ANSWERA substance that consist of different kinds of molecules
What are the two types of mixtures? - ANSWERHeterogeneous and Homogeneous
What is a heterogeneous mixture? - ANSWERa mixture varying composition throughout
a sample
What is a homogeneous mixture? - ANSWERa mixture that has the same composition
throughout
What are physical properties? - ANSWERCharacteristics that can be observed without
changing the substance into another substance
What are some examples of physical properties? - ANSWERcolor, odor, density,
melting and boiling points, hardness, etc.
, What are chemical properties? - ANSWERCharacteristics that can be observed only
when the substance is changed into another substance
What are some examples of chemical properties? - ANSWERflammability and other
types of reactivity, etc.
What are intensive properties? - ANSWERProperties that are independent of the
amount of the substance present
What are some examples of intensive properties? - ANSWERdensity, color,
temperature, boiling point, etc.
What are extensive properties? - ANSWERproperties that are proportional to the
amount of the substance present
What are some examples of extensive properties? - ANSWERmass, volume, energy,
etc.
When we say that lead is a "heavier" (more dense) metal than aluminum, are we talking
about an extensive or intensive property? - ANSWERIntensive
What is physical change? - ANSWERa change that does not change the elemental
composition
What are some examples of physical changes? - ANSWERchanges of state (gas, liquid,
solid), temperature, volume, etc.
What are chemical changes? - ANSWERa change that results in a new substance
What are some examples of chemical changes? - ANSWERCombustion, oxidation,
decomposition, etc.
Plants make sugar from carbon dioxide and water. Is this change physical or chemical?
- ANSWERChemical
Water vapor in the air forms frost. Is this a physical or chemical change? -
ANSWERPhysical
What are the three main states of matter? - ANSWERSolid, Liquid, Gas
What is potential energy? - ANSWERthe energy of the object's interaction with other
objects
What does potential energy depend on? - ANSWERthe object's relative position with
respect to other objects
