Question | Answer |
What are the three Parts of a
SCIENTIFIC EXPLANATION | CLAIM
EVIDENCE
REASONING |
What makes an Explanation SCIENTIFIC? | EVIDENCE |
What is a CLAIM? | It is a STATEMENT that
tells WHAT HAPPENED
or
ANSWERS a QUESTION
in
an INVESTIGATION or EXPERIMENT |
What is EVIDENCE? | It is the DATA COLLECTED
from OBSERVATIONS or TESTS
to SUPPORT a CLAIM |
What are TWO TYPES of
EVIDENCE | QUALITATIVE Evidence
(Describes your OBSERVATIONS. )
and
QUANTITATIVE Evidence
(Describes your MEASUREMENTS) |
What is REASONING? | A way of CONNECTING the EVIDENCE (DATA) to the CLAIM
by using
SCIENTIFIC PRINCIPLES (Rules) |
What are examples of
SCIENTIFIC PRINCIPLES (Rules or Laws) | 1) DENSITY (Mass/Volume) does NOT CHANGE with size of sample.
2) PROPERTIES (Density, Color, Hardness, Solubility, Melting Point) do NOT CHANGE with size of sample.
3) HOWEVER SUBSTANCES INTERACT, the TOTAL MASS of their SYSTEM always REMAINS the SAME. |
WHAT is a CHEMICAL REACTION? | A PROCESS in which SUBSTANCES INTERACT to form NEW SUBSTANCES with different PROPERTIES (color, hardness, solubility, melting point, density). |
WHAT is a CHEMICAL REACTION?
(include word “atoms” in definition) | A PROCESS in which the MOLECULES of Substances BREAK APART and then RECOMBINE their ATOMS in new STRUCTURES to form NEW SUBSTANCES with different properties. |
WHAT is a CHEMICAL REACTION?
(from page 88 to include on substance DECOMPOSING) | A PROCESS in which the MOLECULES of ONE or MORE Substances BREAK APART and then RECOMBINE their ATOMS in new STRUCTURES that are NEW SUBSTANCES with different properties. |
Give examples of DECOMPOSITION Chemical Reactions. | *HYDROLYSIS of WATER to Hydrogen and Oxygen gases
*DECOMPOSITION of Dead animals, trees and plants to mostly Carbon Dioxide and Water |
What is a SUBSTANCE? | It is MATTER that is made of
the SAME TYPE of ATOMS with the SAME MOLECULAR STRUCTURE
all the way through. |
What are MODELS used for? | To REPRESENT things that are
TOO SMALL or
TOO BIG to be seen directly. |
What is a MIXTURE? | It is a combination of MATTER that is made of MORE THAN ONE TYPE of SUBSTANCES (with different molecular structures) which to NOT INTERACT to form NEW SUBSTANCES. |
How do MOLECULES of Substances in a MIXTURE INTERACT? | They DO NOT INTERACT. . They only COMBINE in same space more or less evenly, but WITHOUT SAME RATIO throughout. |
If a Diamond has a hardness of 10.0 and Cubic Zirconia has a hardness of 8.5, Which will scratch which? | A Diamond, being harder, will scratch Cubic Zirconia which is less hard. |
HOW might we KNOW THAT A CHEMICAL REACTION occurs? | There are CHANGES IN PROPERTIES and other
CLUES or SIGNS
that are common to Chemical Reactions |
Name some PROPERTIES of Substances that might change in a Chemical Reaction. | COLOR
HARDNESS
SOLUBILITY IN WATER
DENSITY
MELTING POINT |
What are some CLUES (or SIGNS) that a Chemical Reaction is occurring? | 1) BUBBLING, FIZZING, INCREASE OF VOLUME because of GAS FORMING
2) TEMPERATURE CHANGE without adding or removing heat
3) PRECIPITATE FORMS: a SOLID forms when two LIQUIDS interact
4) LIGHT PRODUCED |
Describe how the molecular structure of a substance helps us understand it? | It is the MOLECULAR STRUCTURE of a SUBSTANCE that causes it to have the PROPERTIES (color, hardness, solubility, melting point, density) by which we know WHAT it is. |
What are the REACTANTS of a Chemical Reaction? | These are the BEGINNING or ORIGINAL Substances—the “Old Stuff” of a Chemical Reaction. |
What is (are) the PRODUCT(s) of a Chemical Reaction? | The END Substance(s) of a Chemical Reaction. |
What is a WORD EQUATION of a Chemical Reaction? | It is a way to use NAMES of SUBSTANCES to DESCRIBE what happens in a Chemical Reaction.
It describes what Reactants “interact to form” what Product(s).
Example:
Copper Sulfate plus acetic acid (reactants) interact to from copper acetate (product) |
Put these words in a sentence that describes THEIR RELATIONSHIP:
ATOMS
MOLECULAR STRUCTURES
SUBSTANCES
PROPERTIES | ATOMS form MOLECULAR STRUCTURES (SUBSTANCES) that have Characteristic PROPERTIES that are the SAME THROUGHOUT any sample. |
What are CHARACTERISTIC PROPERTIES? | These are the Properties that Substances have because of the MOLECULAR STRUCTURE of the ATOMS that make them up. |
What are three different PROCESSES of SUBSTANCES? | 1) CHEMICAL REACTION
2) PHASE CHANGE
3) MIXING (result is MIXTURE) |
In the following 3 PROCESSES of SUBSTANCES tell whether substances COMBINE and HOW.
1) Chemical Reaction
2) Phase Change
3) Mixture | 1) Chemical Reaction: YES, and they COMBINE to form a new substance or substances with NEW PROPERTIES.
2) Phase Change: NO, because a phase change only involves one substance.
3) Mixture: YES, but they COMBINE WITHOUT LOSING their PROPERTIES. |
In the following PROCESS of Substances a tell whether NEW SUBSTANCES are formed and HOW:
CHEMICAL REACTION of Substance(s) | YES, NEW SUBSTANCES are formed after molecules of the REACTANTS BREAK APART and RECOMBINE their ATOMS to FORM new PRODUCTS (Substances or Molecular Structures) that have DIFFERENT PROPERTIES. |
In the following PROCESS of Substances tell whether NEW SUBSTANCES are formed and HOW:
PHASE CHANGE | NO, because the CHARACTERISTIC PROPERTIES DON’T CHANGE when substances move from solid, to liquid to gas phases. |
In the following PROCESS of Substances tell whether NEW SUBSTANCES are formed and HOW:
MIXTURE (Mixing of Substances) | NO, because atoms or molecules just combine to SHARE SPACE MORE OR LESS EVENLY without losing their INDIVIDUAL properties. |
What is an OPEN SYSTEM?
Give example. | A SYSTEM in which SOMETHING can ENTER or EXIT.
Examples:
Alka-Setzer experiment open glass.
Rust on iron in open air. |
What is a CLOSED SYSTEM?
Give example. | A SYSTEM in which SOMETHING can NOT ENTER or EXIT.
Examples:
Closed bag experiment,
Electrolysis |
Describe a Chemical Reaction Process on the MACROSCPIC Level. | 1) SUBSTANCES COMBINE and INTERACT to form NEW SUBSTANCES
2) These have DIFFERENT PROPERTIES from the original substances. |
Describe a Chemical Reaction Process on the NANOSCOPIC Level. | 1) MOLECULES BREAK APART and their ATOMS REARRANGE CHEMICALLY to form NEW MOLECULES.
2) The SAME TYPE OF ATOMS that are in the REACTANTS are in the PRODUCTS. |
Describe a MIXTURE Process on the MACROSCPIC Level | 1) Substances COMBINE, but DO NOT INTERACT CHEMICALLY to form new Substances
2) The Substances are SAME BEFORE and AFTER they Combine.
3) Can’t measure same properties at same temperature BECAUSE each SUBSTANCE reacts to temperature diffferently. |
Describe a MIXTURE Process on the NANOSCOPIC Level | 1) Molecules do NOT BREAK APART and Atoms DON’T REARRANGE. Same MOLECULES before and after.
2) SAME TYPES of ATOMS before and after. |
Describe a MIXTURE Process | TWO or MORE Substances COMBINE, but do NOT INTERACT.
NO NEW Substances
NO SET RATIO among Substances |
Describe a PHASE CHANGE Process | A Process of Change among Solids, Liquids and Gases by ADDING or REMOVING HEAT.
Molecules MOVE FASTER or SLOWER heat is INCREASED or DECREASED.
But the ATOMS ARE THE SAME before and after the phase change. |
What is the SCIENTIFIC PRINCIPLE known as the LAW of the CONSERVATION of MASS?
ANSWER #1 | It is the PRINCIPLE (Rule or Law) that no matter HOW SUBSTANCES INTERACT with each other, the TOTAL MASS of the SYSTEM always REMAINS the SAME. |
What is the SCIENTIFIC PRINCIPLE known as the LAW of the CONSERVATION of MASS?
ANSWER #2 (from 14.1 handout) | NO MATTER HOW Substances INSERT with EACH OTHER, the TOTAL MASS of the system always REMAINS the SAME. Matter is NOT CREATED or DESTROYED.
ATOMS simply REARRANGE to form NEW MOLECULES (NEW SUBSTANCES).
SAME TYPES of atoms B/A. |
When is a CHEMICAL EQUATION BALANCED? | The NUMBER and TYPE of ATOMS on both sides of an Equal Sign are the SAME |
In a Chemical Equation what does the NUMBER IN FRONT of the Atom or Molecule tell you? | It tells you HOW MANY ATOMS or MOLECULES you have. |
In a Chemical Equation what does the NUMBER IN THE SUBSCRIPT of EACH ATOM? | It tells you HOW MANY OF A PARTICULAR TYPE OF ATOM you have in Each Molecule. |
Why does MASS stay the SAME in a chemical reaction? | Because the SAME ATOMS that are in the REACTANTS are still in the PRODUCTS—ONLY REARRANGED. |