Sig figs, graphs, skills etc Flashcards
Why do we use significant figures in science?
Significant figures ensure precision and that is universally accepted across the community.
To what significant figures do we normally round to
MOST OF THE TIME, 2
2 SIGNIFICANT FIGURES,
But also, to the lowest significant figures present in the question
(ADDITION AND SUBTRACTION USE DECIMAL PLACES INSTEAD OF SIGNIFICANT FIGURES)
What is the rule for significant figures when multiplying and dividing
The rule in multiplication and division is that the final answer should have the same number of significant figures as there are in the number with the fewest significant figures
What is the rule for sig figs in addition and subtraction?
ADDITION AND SUBTRACTION DOES NOT USE SIGNIFICANT FIGURES.
What is the rule for sig figs in addition and subtraction?
ADDITION AND SUBTRACTION DO NOT USE SIGNIFICANT FIGURES.
THUS, THE ANSWER RELIES ON THE SMALLEST DECIMAL PLACE WITHIN THE QUESTION AND IT MUST BE ROUNDED ACCORDING TO THAT NUMBER.
THEREFORE, SMALLEST AMOUNT OF DECIMAL FIGURES FOR ADDITION AND SUBTRACTION, BUT SMALLEST NUMBER OF SIG FIGS FOR MULITPLICATION AND DIVISION
Things to remember for graphs (special)
- The vertical and horizontal scales can be different (they can also start at different initial values and go up by different amounts. Also, origin does not have to be 0,0)
- If the first value does not start on the y-axis, then draw a dotted line of best fit from the very start all the way to the first point
- Always write titles with units of measurement next to them in brackets
- Draw a curve or a line of best fit based on what it looks like
- The dependent variable is the y-axis while the independent variable is the x-axis
- WHENEVER YOU’RE FINDING THE GRADIENT OF THE LOBF, DRAW A RIGHT-ANGLED TRIANGLE AND MARK THAT IT IS RIGHT ANGLED
Things to remember for graphs (basic)
- Use a ruler
- Include a title and subtitles for each section (with units of measurement)
- Draw crosses instead of colouring dot points
- Include a line of best fit
Things to remember for column graphs
Include a title
Colum heading including the units of measurement
The INDEPENDENT VARIABLE IN THE LEFT COLUMN (x)
The DEPENDENT VARIABLE IN THE RIGHT COLUMN (y)
Therefore, the Independent variable comes before the dependent variable in a column graph
The ‘sample’ section with numbers 1 to 10… comes first
How many sig figs are in 100?
What about 1000?
100 HAS 1 SIGNIFICANT FIGURE
1000 ALSO HAS 1 SIGNIFICANT FIGURE
BOTH NUMBERS ONLY HAVE ONE SIGNIFICANT FIGURE, BECAUSE TRAILING ZEROES DO NOT COUNT AS SIGNIFICANT FIGURES UNLESS THERE IS A DECIMAL POINT THAT IS SATISFIED
How many sig figs in 100. ?
- will have 3 significant figures, since there is a specified arrangement of a DECIMAL POINT
How can you write 1000 as three significant figures? (1000 has one significant figure)
USE SCIENTIFIC NOTATION
THUS, THE ANSWER WILL BE 1.00 X 10^3
It cant be 0.01 x 10^5 because 0.01 is also one significant figure, since zeroes at the front DO NOT count