Chemist

STUDY
PLAY
Science
a systematic way of learning about the world by collecting information. It is a way of thinking that helps people understand and gain knowledge about the world around them.
Scientific inquiry
refers to the different ways that scientists explore the world. It is the way scientists have come to understand so much and how they can continue to learn. It involves observation, research, a hypothesis, experiment, data collection and analysis, a conculusion and communicating ideas and results
scientific method
a way to conduct scientific inquiry. It guides scientists as they ask and answer questions about the world. There are many ways to explore science, so different books, websites, and documents describe the scientific method and scientific inquiry in different ways.
observation
Scientists explore and collect information with their senses (smell, sight, sound, touch, and taste) and ask questions that they would like to answer. Questions guide scientists in their research and can usually be answered by collecting evidence.be It is not based on evidence. A scientific question is answered using evidence.
research
Many scientists and students spend time reading papers and books on past studiesh before beginning their own experiments. Often they will find that other scientists have conducted experiments that try to answer a similar question
credible
another word for trustworthy
websites
can be updated with new information almost immediately. Updating the information in a book takes much longer.
hypothesis
a predicted answer to a scientific question or an educated guess that may explain an observation.
testable
A scientific hypothesis must be ***
one
Scientists must be sure to design the experiment so that only *** factor is tested at a time. This way, scientists will know that their results are directly related to the one factor that was changed. If the experiment is not designed carefully, the results may be confusing and will not help to assess the hypothesis.
data
pieces of information collected before, during, and after an experiment. It is important to keep detailed notes so that it can be analyzed after completing the experiment to determine the results. Sometimes this information may make more sense in a graph or as a picture.
repeat
what scientists do to make sure that they collect accurate data so that they can trust their results and to see if they can obtain the same results each time. as a singular
communicate
Scientists will often report their findings in journals or speeches to tell others what they have learned. They may create diagrams or other images to show their results. We say that they *** their results.
variables
factors that can be changed and controlled in an experiment
independent variable
also known as the manipulated variable
dependent variable
the variable scientists observe or measure to see if it is affected by a change in the independent variable. This is also known as the responding variable.
x-axis
horizontal axis on a graph
controlled experiment
an experiment in which all conditions except one are held constant. They eliminate confusion about the outcome because only one factor is changed at a time.
controlled variables
sometimes known as constants, are things that should not change during an experiment. Experiments often have many of these to make sure that the comparisons being made are meaningful.
theories
explanations of an event or phenomenon that is well supported by data. They have the following things in common: They are not facts. They may change as more information becomes available. The best ones have been tested over and over, producing the same results. They attempt to explain why something occurs. They can be used to predict the results of future observations.
law
a description of a natural event or phenomenon shown to occur again and again under the same conditions. It describes the observed pattern without trying to explain it. They are usually accepted as true and universal. They are well supported by observations
measurements
provide scientists with a quantity. A quantity describes how much of something there is or how many of something there are.
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.
mass
measure of the quantity (or amount) of material in a substance. Usually measured with a balance scale
weight
a measure of the pull of gravity beween an object and the earth (or the planets, sun, etc.) usually measured on a weighing scale or spring scale
newtons
unit used by scientists to measure weight
pounds
In the U.S. customary units used to measure weight (abbreviated lb)
meter
standard unit used by scientists to measure length
proportional
changes at a constant rate
length
a measure of how long an object is or the distance an object spans
meter
the standard unit scientists use for measuring length
liter
scientists use this unit to measure volume or cubic centimeters
volume
length (l) x width (w) x height (h)
thermometer
a device that measures temperature
degrees
unit scientists use to measure temperature
273.15
number added to the Celsius temperature to convert to Kelvin temperature
Fahrenheit
the temperature scale commonly used in the United States.
density
the amount of matter per unit of volume. This measures how much matter occupies a given amount of space. An object that is very dense is very compact, so it has a large number of particles in a confined amount of space.
pressure
the amount of force exerted per unit area.
force
the amount of push or pull on an object.
barometer
this or a manometer is used to measure air pressure
energy
a measure of the ability to do work or generate heat. Some of these forms are mechanical, chemical and thermal
units to measure energy
Joules (J), calories (xal), and electron volts (eV)
customary units
pounds, stones, inches, feet, miles, pints, quarts, gallons, degrees Fahrenheit, British Thermal Units (BTU), are examples
metric system
Scientists often use this system of measurement developed in France in the 1790s. It was the first standardized system of measurement
metric prefixes
Some things scientists want to measure may be very large. Other things may be very small. To work with either extremely large or small numbers, scientists use these. Examples: Tera- Giga- Mega- Kilo- Hecto- Deca- (no prefix) Deci- Centi- Milli- Micro- Nano- Pico-
metric bases
meter, liter, gram
kilometer
1000 meters equals
force
mass x acceleration =
Pure substance
a uniform substance made up of one type of particle, which can be either an element or a compound.
element
a pure substance that cannot be broken down by normal chemical or physical means. These are are considered the simplest substances. It is made of only one type of atom. It is identified by its atomic number
allotropes
different forms of the same element in the same physical state of matter.
8
the atomic number of oxygen
oxygen
the most common element in the earth's crust
tin
the symbol for this element is Sn. The symbol comes from the Latin name "stannum" It is very malleable and ductile
binary compound
a compound made up of two different elements
ternary compound
a compound made up of 3 different elements.
compound
a pure substance made up of two or more elements joined in a defined ratio.
John Dalton
developed the atomic theory of matter
volume
the amount of space that matter occupies or takes up