The Core of Chemistry 96 pg guide Flashcards
What is a theory?
An explanantion of some event or phenomenon that is well supported by data.
- not facts
- ‘may change with discovery of information
- tested over and over with same results
- why something occurs
- predict results of future observations
What is a law?
A description of a natural event or phenomenon shown to occur again and again under the same conditions. A scientific law describes the observed pattern without trying to explain it.
- accepted as true and universal
- well supported by observations, experimentation, and data
- can be challenged and possibly disproven although it is very rare
Accuracy
Refers to how close a measured value is to the true measurement (true value) of something
Precision
Refers to the ability to take the same measurement and get the same result over and over.
Weight
A measure of the pull of gravity between an object and the earth.
It is actually a measure of force
weight= mass x gravity
Weight on other planets based on 100 pounds
- Mercury- 38
- Venus- 88
- Earth- 100
- Mars-38
- Jupiter- 235
- Saturn-105
- Uranus- 89
- Netune- 120
Density
The amount of matter per unit of volume
- density= mass/ volume
Convert oC to K
oC + 273.15= K
Convert oF to oC
F= (1.8 x (C)) + 32
Convert oC to oF
C= F - 32
1.8
What is pressure? What is the formula?
The amount of force exerted on an area.
pressure= force/area
Force
The amount of push or pull on an object.
What are the two types of matter? Name their subcategories?
- Pure Substance
- Compounds
- Elements
- Mixture
- Homogeneous (soda pop, brass)
- Heterogeneous (pizza, salad)
What are the properties of matter?
- Physical properties
- Chemical properties
Define: Physical Properties of Matter
A property of matter that can be observed without changing the substance into another substance.
E.g. density, color, boiling point, and melting point.
Define: Chemical Properties of Matter?
Determined by the ability of a substance to react with or change into another substance.
What is toxity?
The potencial of a substance to have a harmful effect on an organism. It is a chemical property because you can only determine toxicity by observing how a substance reacts with another substance.
Can vitamins be toxic?
Yes, in extremely large quantities.
Is toxicity related to the amount of a substance?
Yes
Which word correctly expresses that something is not flammable: Inflammable or Nonflammable?
Nonflammable.
Inflammable is actually a synonym for flammable.
What is the fire triangle? What are it’s conditions?
The fire triangle is made uo cerain conditions that are needed for a fire to occur.
- Fluel
- Oxygen
- Energy
Define: Crystalline solids or Crystalline structure
A solid made up of atoms or molecules that are organized in specific repeated patterns. (e.g. quartz, cotton candy)
Define: Amorphous solids
Solids made up of atoms or molecules that are locked into place. However, those atoms or molecules do not organize into a specific form or neat, repeating structure. (e.g. glass, wax, rubber)
What is Viscosity?
A property of liquids that describes the “thickness” of the material. It is a measure of the liquid’s resistance to flow. The less viscous a liquid is (the lower its viscosity), the more easily it flows.