Chapter 1/2.1 Flashcards
What were alchemists concerned with?
- Changing other metals into gold
- Create/Find the philosopher’s stone
- Develop an elixir of life
Where does the word “chemistry” come from?
The word “alchemy”.
What is an alchemist, and what do they believe?
An alchemist is someone who uses chemicals for medical, spiritual, and magical purposes. They believed that the physical and spiritual world are inseparably connected.
Who is Alexander Fleming and what did he do?
He was a Scottish scientist. He discovered that bacteria did not grow in the presence of mold.
Who was Antoine Lavoisier and what did he do?
He was a scientist who invented a scale that measured mass extremely accurately, to the nearest 0.0005 gram. He also discovered that oxygen is needed for a material to burn.
What is the scientific method? What are the steps?
It’s a logical, systematic approach to the solution of a scientific problem. The steps are:
- Make observations
- Make hypotheses
- Experiment/Test a hypothesis
- Develop a theory
What does it mean to make an observation?
When you use your senses to obtain information.
What is the difference between an observation and a conclusion?
Observation: relies on what can be observed by the senses. What we observe can not be used to make presumptions.
Conclusion: to make a judgement based on one’s observations. Often requiring one to make assumptions.
What is a hypothesis?
A proposed explanation for an observation?
When making a conclusion, how should you properly state your conclusion?
“The experiment failed to disprove that..”
What is an experiment?
A procedure used to test a hypothesis
What is an independent variable? What is a dependent variable?
An independent variable is the variable you change during an experiment. It is also called the manipulated variable.
The dependent variable is what depends on the independent variable, or is observed during the experiment. It is also called the responding variable.
How do the results of an experiment come to be accepted?
The experiment must produce the same results no matter how many times it is repeated or by whom.
What is a theory?
A theory is a well-tested explanation for a broad set of observations.
What is a scientific law?
A concise statement that summarizes the results of many observations and experiments. Cause and effect. It doesn’t try to explain the relationship it describes. “This happens, then this happens..”
Ex) SL: The apple will rot on the 7th day it is left outside
Theory: The apple will rot on the 7th day it is left outside due to excessive sunlight and bacteria.
What is a substance?
Matter that has a uniform and definite composition
What is a physical property? What are some examples of physical properties?
A quality or condition of a substance that can be observed or measured without changing the substance’a composition.
Ex) hardness, color, conductivity and malleability
What does malleable mean?
It means the substance can be hammered into sheets without breaking
What can physical properties help do?
Identify substances
What is an extensive property? What is an intensive property? What are these properties sub-categories of?
Extensive Property: Depends on the amount of the matter in a sample. Ex) mass, volume, length, weight, shape.
Intensive Property: DO NOT depend on the amount of the matter present. Ex) color, odor, luster, conductivity
What is mass?
The measure of the amount of matter the object contains. Ex) a 100 foot balloon (hallow) has less mass than a 5 foot tall dense statue.
What is volume?
The measure of the amount of space occupied up by the object. Ex) A 100 foot balloon (hallow) has more volume than a 5 foot tall dense statue.
What is the difference between a pure substance and a mixture?
A pure substance is completely made up of that substance with no other substances within and it has a definite composition. A mixture has a variable composition with different substances together.
What are the states of matter?
Solid, liquid, gas
