CHAPTER ONE: CHEMISTRY AND MEASUREMENTS Flashcards
In general, what is Chemistry?
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The study of matter (all the substances that make up our world)
More specifically, what is Chemistry the study of?
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Chemistry is the study of the structure, physical properties and transformation (chemical properties/reactions) of matter.
Define MATTER
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Matter is anything with mass (weight) and volume (takes up space). Has atoms.
Explain MASS vs. WEIGHT
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Mass- the amount of matter contained in an object. Does NOT depend on location.
Weight- the amount of force exerted by gravity on an object. DOES depend on location
Give the equation for FORCE
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Force=mass x acceleration (F= m x a)
EX: Newton (N) = (kg)(m/s^2)
Along with changes, there is ________ being transformed. It can be ________, ________, ___________, _______________.
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Energy.
Heat, light, sound, electricity
What are the 3 main kinds of substances from a chemistry point of view?
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- Elements
- Compounds (chemically bonded atoms of different elements)
- Mixtures (any number of different elements of compounds physically mixed together- not bonded). Air is a mixture of nitrogen and oxygen.
How do you differentiate between PURE SUBSTANCE and a MIXTURE?
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Can it be separated without changing the substances present?
YES- mixture (more than one substance “mixed”)
NO- pure substance
How do you differentiate between HETEROGENOUS and HOMOGENEOUS MIXTURES?
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Can you see the different substances?
YES- heterogeneous
NO- homogeneous
How do you differentiate between a COMPOUND and an ELEMENT, in terms of pure substances?
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Can it be separated at all?
YES- compound
NO- element (example: GOLD- cannot make it a simpler substance; only made of itself)
Differentiate between these 2 types of matter: PURE SUBSTANCE/CHEMICAL and MIXTURES OF SUBSTANCES
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Pure substance/chemical= anything that can be described by a chemical formula. Ex: AR (argon gas), H20
Mixtures of substances= cannot be described by a single chemical formula
What is the SCIENTIFIC METHOD? (definition and 4 specific steps)
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Definition: General principles or guidelines for how a scientist thinks.
- OBSERVATIONS: data, natural phenomena, natural laws
- HYPOTHESES: tentative proposal (testable)
- EXPERIMENT: test (control of all variables except those of interest)
- THEORY/MODEL (CONCLUSION): explanation which allows for prediction
How many ELEMENTS exist?
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118
Are ELEMENTS naturally occurring or man-made?
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Both.
FOUND IN NATURE: Elements from 1-92 can be found in nature, with the exception of 43 and 61.
MAN-MADE: The first manmade elements were made in 1939 at UC Berkeley. Elements 93 and on are all man-made.
The PERIODIC TABLE is organized by ______________________
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Similarity in element properties
Elements on the Periodic Table have a ______ and a __________. List 5 rules about how they should be written.
F
Elements on the Periodic Table have a NAME (language dependent) and a SYMBOL (universal).
5 rules about how they should be written:
- spelling counts
- do NOT capitalize
- the symbol will be 1 or 2 letters (3-letter symbols represent unnamed elements)
- 1st letter of symbol capitalized
- 2nd letter of symbol must be lower case
What are the three states of matter (and the color) at room temperature?
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SOLID- black
LIQUID- blue
GAS- red
How is the Periodic Table organized?
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It is organized into GROUPS vertically- the columns-there are 18 groups (#1-#18); grouped by similar properties.
It is organized into PERIODS horizontally- the rows (#1-#7), grouped by having the same number of atomic orbitals.
What is SCIENTIFIC NOTATION? How are numbers written in Scientific Notation?
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Scientific notation is a way of writing numbers that are too big or too small to be conveniently written in decimal form. Scientific notation has a number of useful properties and is commonly used in calculators and by scientists, mathematicians and engineers.
In scientific notation, there are three parts: a coefficient, a power of 10 and a measurement unit.
All numbers are written in the form a x 10^b
Examples:
- 0.00865= 8.65 x 10^-3
- 57827= 5.7827 x 10^4
What is a CHEMICAL?
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a substance that always has the same composition and properties wherever it is found
What are the 3 common scales of TEMPERATURE and their relative numbers for the lower limit (absolute zero), freezing and boiling?
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Kelvin (K) 0K……………273 K………….373K
Celsius (C) -273C………………..0C…………..100C
Fahrenheit (F) -460F……………….32F………….212F
What is the International System of Units (SI, or Systeme International)?
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The SI is a modification of the metric system that was adopted in 1960 by scientists throughout the world. It is now the official system of measurement throughout the world except for the USA.
MEASUREMENTS:
* how is LENGTH described in Metric, SI, and the US system?
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Metric- meter (m)
SI- meter (m)
US- feet (ft)
MEASUREMENTS:
* how is VOLUME described in Metric, SI, and the US system?
M
Metric- liter (L)
SI- cubic meters (m^3)
US- gallon (gal)