chapter 1 Flashcards
what are the 4 main things that chemistry studies?
- Matter and its properties,
- Interactions of matter.
- The changes matter undergoes
- The energy associated with the change
what is matter?
anything that has weight and takes up space or has volume.
what are the different kinds of matter?
- liquid
- solid
- gas
- plasma
what are the 6 chemical reactions that changed history?
- Fire - maillard reaction (sugars and aminos when reacted to high temp)
- bronze
- fermentation
- saponification (soap)
- silicon
- the haber-bosch process (made fertilizer, food, bombs).
why was the the haber-bosch process so important
better fertilizer which increased food. Also made used to make bombs. Important discovery
what is the most important natural reaction?
photosynthesis
how does photosynthesis work?
it converts water and co2 into sugar and oxygen
why is photosynthesis important?
it takes the non-living (wtaer and co2) and converts them into the building blocks for the living (sugar and oxygen)
what does rationalism mean in science?
to think with reason and logic
what subject is an example of rationalism
math
what does A Priori mean in rationalism?
knowledge exists independently from experiences.
what are some characteristics of empiricism?
evidence is required to form ideas. knowledge is constantly changing as new ideas falsify old ones.
what does A posteriori mean in empiricism?
the knowledge that depends on empirical evidence.
what does empirical evidence mean?
the information received through experimentation.
newton notices an apple falls on his head. What stage in the scientific method is this?
observation.
without ___ science becomes static.
revision
what is the definition of hypothesis?
a tentative explanation of observation / an educated guess
what does tentative mean?
not fixed
what is a theory?
a set of tested (need to do experiments) hypothesis that provide an explanation of an observed behaviour
what does a law mean?
a summary of observed behaviour
what is the constraints of a law
it does not tell you why something happens
what can a theory do that a law cannot
a theory explains why something happens. Ie: Law of gravity vs theory of relativity.
what are the two types of observations in science?
qualitative and quantitative
explain the differences between quantitative and qualitative observations.
Quantitative means observations that do not include numbers.
while quantitative means observations that include numerical measurement.
using a frog as an example, use quantitative and qualitative observation.
former - frog is green and is noisy.
latter - frog weighs x pounds and is x long in cm.
which two observations is mainly used in science?
quantitative
what is the definition of plasma?
a gas of ions (electrically charged atoms)
definition of solid
something w a fixed shape and volume
definition of liquid
A liquid conforms to the shape of its container but retains a constant volume
definition of gas
has no fixed shape, fills the volume of its container, is highly compressible.
explain a solid on a molecular level
the molecules in a solid do not move but they vibrate
explain a liquid on a molecular level
the molecules in a liquid can move around but must maintain the shape of their container.
explain a gas on a molecular level.
the molecules in a gas can travel freely.
do molecules in gas travel fast or slow?
fast
explain plasma on a molecular level
like gas but with charged ions.
where does plasma take place and what happens?
at very high temperatures in stars, atoms lose their electrons.
what are the phase changes starting from solid and going linearly to the right?
solid – MELTING — liquid — VAPORIZATION — gas — ONIZATION — plasma
starting from plasma, state the phase changes going to the left.
plasma – DEIONIZATION – gas — CONDENSATION – liquid — FREEZING — solid
what is the terminology for a solid converting to a gas, and what is an example of that?
sublimation, Ie: dry ice.
what is the terminology for what a gas converts to a solid
deposition
convert a solid into a liquid and vise versa.
Melting –>
convert a liquid into gas, and vise versa.
vaporization –>
convert gas into plasma and vise versa
ionization —>
what is the terminology used to describe the behaviour of particles
kinetic molecular theory
what is kinetic energy?
energy of motion
explain the kinetic molecular theory.
- all matter is made up of tiny particles (molecules/atoms)
- particles are constantly moving
- there’s empty space between particles
- particles move because of energy
T/F - particles will move at anything above absolute zero
true
what influences kinetic energy?
temperature - higher temperatures, higher kinetic energy. vise versa
what is the relation between kinetic energy and the three main states of matter?
the higher the kinetic energy, the more likely it will turn to a liquid or gas.
everything that is not matter is __
energy
anything that is mass is ___
matter (anything that can you can weigh)
The classification of matter seeks to find out what mainly?
does it have a constant composition
explain the process of classification of matter! (make a diagram to make it simple (this is the yes/no question)
- does the matter have a constant composition.
- no, then it is a mixture. Next, is it uniform throughout? if yes - then homogenous, if no then heterogeneous
- yes, then it is a pure substance. Next question - can it be simplified chemically? If yes, then it is a compound; if no, then it is an element.
what does uniform mean
having the same form
how should a homogenous thing look like?
should have an even consistency
how should a heterogenous thing look like?
should not have uniform or consistency
what is the main difference of the bonds between a mixture and a compound?
in a mixture, there are no bonds between the elements, whereas a compound has bonds between the elements.
give examples of an element and a compound
hydrogen in the former, and h20 in the latter
explain a pure substance vs a mixture
pure substance is a type of matter that has the same properties and composition throughout the sample.
mixture - a group of two or more substances, and the components are not chemically bonded together.
what is an element?
is the simplest substance and is comprised of only one type of atom.
which metals conduct electricity well and which do not?
metals
metalloids do not
what are the three types of elements?
metals, metalliods, non-metals
are most metals solid?
yes except murcery
which element group does shiny items belong to
metals
on the periodic table, what # do the elements occur that are not natural?
93 onward are synthetic
what element makes up majority of the universe?
hydrogen
what are the two main elements of the earth’s crust?
oxygen and silicon
why does rusting occurs
when oxygen combines with a metal
where does silicon exist in the 3 main elements
metalliod
what is a real life example of silicon
sand
which element dominates the whole earth and where does it reside
iron in the earths core
what do the magnetic fields do?
protect s from cosmic radiation
what element is the human body mainly comprised of, followed by what, then followed by what?
oxygen then carbon, then nitrogen
which elements are noble gases?
helium, argon, neon, crypton, xenon, and radon
how many valence electrons do helium have?
2
How many valence electrons do argon, neon, crypton, xenon, and radon have?
8
are noble gases stable or unstable?
stable
where are noble gases located on the periodic table?
refer to the image (its to the far right)
where are metals located on the periodic table? and which element is the exception?
located to the left of the staircase &
Helium
locate the alkali metals
all the elements below helium
Alkali metals are not reactive T/F
F
Name the three characteristics of matter of solids
- fixed shape
- fixed volume
- molecules vibrate
what is the definition of an element and where would you find the elements?
a substance that cannot be broken down into anything simpler. They are located on the periodic table of elements
all matter can be broken into what two things?
pure substance and mixture
what can pure substances be broken down into?
elements and compounds
ignore
ignore
what can mixtures be broken down into?
homogenous and hetrogenous mixtures
what are the two main characteristics of a mixture?
a random blend of two or more substances.
can be separated.
what does a compound mean?
a compound is a pure substance of two or more substances chemically combined
how many atoms are in an element?
only type of atom
what do the numbers above the elements represent on the periodic table?
the number of protons
what is a particle of a compound
a molecule
what is an example of a compound?
h2o
what happens when you mix elements together?
no new bonds are being formed
What is the fundamental difference between a mixture of elements and a compound?
a mixture of elements: no new bonds.
compounds: has bonds
What determines the melting and boiling points of substances?
melting point: the temperature at which molecules in a solid can move past each other and form a liquid.
Boiling point:
temperature is the ___
kinetic energy of the molecules
what does it mean when the molecules vibrate more and more?
the temperature is increasing
what determines the bioling point
when the kinetic energy of liquids increases, the molecules move faster and faster
