Chapter 2 Flashcards
convert 1 meter into nano
1m = 10^9 nm
convert 1 meter into milli
1m = 10^3 mm
convert 1 meter into centi
1m = 100 cm
dimensional analysis: rearrange the question 5 meters/seconds X (times) 10 seconds
5 x 10 x m/s x s. Then cross out the two sā. You then get 50 m
why is it important to make measurements in science?
science is very quantitative and collects data
Is metric used most in science true or false?
True
all quantitative data requires a __ and a __ unit
number; unit
what is the purpose of using scientific notation?
used to simply very large or very small numbers
what are the two things required for scientific notation?
a number between 1 and 10, and a power of 10
how would you write 0.000012 in scientific notation
1.2 x 10 ^-5
ignore
ignore
Scientific notation: if you have a very large number, it is represented as?
10^n
Scientific notation: if you have a very small number, it is represented as
10^-n
when you have a really big number, like 120000, what is the scientific notation? What would the process look like?
count/move the decimal place through each zero till you place the decimal spot in between 1 and 2. Then count the number of moves as the 10^n
using a calculator: you replace 10 with what?
E on calculator
Calculator: After youāve used E for your equation, and want to see the number in scientific notation, what do you do?
press 2nd then SCI.
Which SI unit and symbol is represented for Mass?
kilogram; kg
Which SI unit and symbol is represented for length
Meter; M
Which SI unit and symbol are represented for Time?
Second; S
Which SI unit and symbol is represented for temperature
Kelvin; K
Which SI unit and symbol are represented for amount?
Mole; mol
Convert 1 meter into kilo
1m = 10^-3 km
ignore
ignore
when something says scaling factors, what does it mean?
the symbols used for measurements (kg, cm, m etc)
Definition of mass
quantity of matter inside an object
The process of determining mass is called?
weighing
do not confuse mass with ___
weight
what is the key difference between mass and weight?
mass is the quanity of matter in an object; weight is the gravitation force acting on an objectās mass
why is the kelvin scale important?
because it is based on molecular motion
at 0 K, what is the kinetic energy?
zero kinetic energy
when kelvin is at zero, celsius is at?
-273.15
what are 2 examples of the derived units of area and volume?
cm^2; cm^3
Density is the
ratio of mass to volume
what is volume
the amount of space a substance has in a container
solids = g/__
cm^3
liquids = g/__
ml
gases/g/__
L
ignore
ignore
why do you use g/L when measuring gas?
because gas takes up a lot more space
how do you determine volume?
by water displacement
who discovered volume?
archimedes
how would you approach the question: you find that a n in ml of a liquid weights n in g, what is the density?
n in g/n in ml
what is the formula for density?
mass divided by the volume
when you heat up an object, what happens to the density
it changes
when a question uses the wording ā it displaces by x amountā what are they really asking?
the volume
density = what / divided by what
mass divided by volume
what unit measurement is volume always displayed as ___
cm^3
if you make measurements persistently but not accurately there is no scientific value
true
what are the two types of errors?
random errors and systematic errors
what are the most common type of errors
random errors
meaning of random errors
-results from the limitations of the experimenters skills
meaning of systematic errors
inherent errors in instruments and cause consistent errors
how do you reduce random errors?
reduce by making repeat measurements
what do you do if you run into systematic errors
you need to find the source of the error
what is an example of a systematic error?
a faulty balance
measuring meniscus in a container (its just a substance) the measurement looks concave. Which part do you measure?
the bottom of the concave meniscus
always estimate __ the lines
between
what are significant figures used for
used to express the uncertainty in a measurement
6.003 - how many significant numbers
4
0.00035 how many significant numbers
2
0.00035000 how many significant numbers
5
ātrailing zerosā reffer to what
zeros that come after a significant number after a decimal point. IE: 0.035000 (the last three zeros are significant)
10,000 has how many significant figures?
1
do the zeros in 0.0025 count as significant numbers?
no
101 - does the zero count as a significant number?
yes
all non zero digits do/do not count as significant figures?
they do count
zeros in-between number do or do not count as sig figs
they do count
1.00, how many sig figs?
3
differentiate the sig figs of 10,000. & 10,000
10,000. = 5 10,000 = 1
how many sig figures have in 1.050
4
150.0 has how many sig figs
4
if 150 has 2 sig figs, how would you write it in scientific notation?
1.5 x 10^2
if 150 has 3 sig figs, how would you write it in scientific notation?
1.50 x 10^2
round these two significant figures to 2 sf: 3.15 & 1.36
3.2 1.4
0.04450 has how any sig figs?
4
when something has a definitive answer. How many sig figs are there?
infinite number
how many sig figs in 1.000 x 10^5
4 - the digit 1 and the trailing 0ās (just ignore the 10^5)
how many sig figs in 0.00002
1 (do not count the leading zeros)
determine the amount of significant figures and the range of precision: 0.00120 **even if you get these right, put it that you got them wrong so you can practice more
3 sig figs - 0.00119 to 0.00121
determine the amount of significant figures and the range of precision: 120. **even if you get these right, put it that you got them wrong so you can practice more
3 sig figs, 119 to 121
determine the amount of significant figures and the range of precision: 12.00 **even if you get these right, put it that you got them wrong so you can practice more
4 sig - 11.99 to 12.01
determine the amount of significant figures and the range of precision: 1.20 x 10^3 **even if you get these right, put it that you got them wrong so you can practice more
3 sig figs 1190 to 1210
what is the rule about multiplying/dividing significant figures
of sig figs in the answer should be the same as the measurement with the least number of sig figs
sig fig addition/subtraction rule
the number of sig. figs. in the answer is limited by the least number of decimal place
when multiplying 5.02 x 89.665 x 0.10, how many significant figures would the answer have?
2 sig figs (lowest sig figs in question was 0.10 (2 sig figs)
1 ml = ___ g?
0.768
1 ml= __ L?
10^-3
1 kg = ___ g?
1000
There are three rules on determining how many significant figures are in a number:
Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant.
a change in color, the formation of bubbles, the spontaneous increase or decrease in temperature are signs of a
chemical change
a change in color, the formation of bubbles, the spontaneous increase or decrease in temperature are signs of a
chemical change
reversed
chemical change
a change in color, the formation of bubbles, the spontaneous increase or decrease in temperature are signs of a
phase changes are a
physical change
*reversed card - physical change
phase changes are a
what are the qualitative observation to make for solids:
colour or colourless
what are the qualitative observation to make on liquids and gas
liquids : colour or colourless, clear or cloudy
gas - colour or colourless
