Unit 0 Flashcards
study for quiz
Scientific Method
evidence based method of inquiry
-evidence is collected through a series of experiments that are as accurate/ unbiased as possible
-as more information is collected, conclusions and our understanding of science changes
chemistry
the studdy of matter, its compositions, and its properties
matter
anything that has volume and mass
-“anything that takes up space”
composition
parts of matter present in specific proportions
properties
the attributes to distinguish between matter (scent, color, temperature, etc)
atoms
the smallest building block of matter
molecules
groups of atoms that are the same atoms
-ex: O2
compounds
groups of atoms that have different atoms
-ex: H2O
elements
different atoms organized by mass on the periodic table
Physical Properties
can be observed or seen without a change in composition
ex: color, shape, size, mass, texture, melting point, magnetism, density, mallubility, smell, temperature, state of matter etc.
Chemical Properties
are observed/ measured only with a change in composition
ex: toxicity, reactivity, corrosiveness, flammability, acidity, radioactivity etc
Physical Changes
change that does not alter the composition of the matter that undergoes the change
sign: phase change
chemical changes
change that alters the composition of the matter that undergoest the change
signs: change in smell, color, texture, energy (glowing or on fire), pH, an new material forming (precipitate), a solid from a liquid
pH
the strength of an acid or base
error/uncertainty
the trustworthyness of a measure
kilo (k)
1000 (10^3)
milli (m)
0.001 (10^-3)
micro (μ)
10^-6
nano (n)
10^-9
pico (p)
10^-12
mass (unit)
gram (g)
length (unit)
meter (m)
time (unit)
second (s)
temperature (unit)
Kelvin (K), Celcius (℃)
amount (unit)
mole (mol)
current (unit)
ampere (A)
Add/Subtract significant figures
keep as many decimal places as the number with the least amount of sig figs
-ex: 2.11 + 3.0 + 1.013 = 6.1
Multiply/Divide significant figures
keep as many significant figures as the number with the least amount of significant figures
-ex: 4.567 x 1.4 = 6.5
Scientific Notation
A x 10^n
A is a number between 1 & 10
n is the exponent
-ex: 10^-3=0.001
-ex: 86,400 = 8.64 x 10^4
Accuracy
how close a measured quantity is to the accepted value
Precision
how close measured values are to each other
-shows reproducibility
Average (x bar)
measures a central tendency of a set of numbers
Standard Deviation
the amount of deviation from the average
(Spread)
-always rounded to one sig fig
-
formula for average
X1+X2+X3…/n where n= number of measurements
-have the mean go out to the same amount of decimals as st. dev.
-ex: 5.20 +/- 0.05
formula for standard deviation
√(x1-avg,)^2 + (x2-avg)^2 + …
————————————-
n-1
where n = number of measurements
Density
property of a substance that can be calculated as mass/volume
solution
a homogeneous mixture: a mixture where all the materials present are present in the same composition
Graph
a diagram depicting the relation between variables
variables
quantities that can change
