Properties of Substances

pre-fix #, basic units, scientific notation, and sig. fig.

Unit, symbol, approximation of length

meter, “m”, a door is 2m tall

Unit, symbol, approximation of mass

gram, “g”, a 5c coin weighs 5g

Unit, symbol, approximation of volume

litre, “L”, a grapefruit occupies 1L of space

Unit and symbol of time

seconds, “s”

Mega

“M“ 1,000,000

kilo

“k” 1,000

hecto

“h” 10

deci

“d” 0.1

centi

“c” 0.01

milli

“m” 0.001

micro

“mew’ 0.000001

nano

“n" 0.000000001

Change 1234 to scientific notation

1.234 × 10³

Change 0.05678 to scientific notation

5.678 × 10^-2

rule when multiplying / dividing scientific notation

multiply / divide decimal parts and add / subtract exponents

rule when shifting scientific notation

decimal decrease exponent increase, and vice versa

rule when adding / subtracting scientific notation, and easier to …

exponent must same, and easier if shift up to larger exponent

Define accuracy

How close a measurement is to the actual value or known measurement

Define precision

Repeatability of measurements

Define significant figures

All the certain figures and plus the first uncertain figure

Six rules for counting significant figures

1. All nonzero digits are significant

2. all zeros between nonzero digits are significant

3. Final zeros to the left of a decimal point is significant

4. Final zeros to the left of a UNDERSTOOD decimal point are not significant

5. Final zeros to the right of a decimal point are significant

6. Zeros @ the beginning of a number are NOT significant

When converting from decimal to scientific the # of sig. fig. must …

stay same

Rule for multiplying and dividing sig. fig.

Product will only have as much sig. fig as the number with the least sig. fig.

Rule for adding and subtracting sig. fig.

Answer will have the uncertain digit at the same place as the most uncertain digit in the question e.g. 121 + 100 = 200 as the “0” in the tenth place is most uncertain, hence in “200” the uncertain digit is same.

The rule for uncertainty on a measurement, the last digit is assumed to be …

plus or minus 1

Define boiling/condensing point

The temperature at which a liquid/gas changes into the gas/liquid phase

Define freezing/melting point

The temperature at which a solid/liquid changes into the liquid/solid phase

Solid

rigid, don’t easily change shape, very small changes when experiencing heat and pressure

Liquid

change shape to container, small changes when experiencing heat and pressure

Gas

change shape to container, large changes when experiencing heat and pressure

Gases have … separation, meaning it can be …

large; compressed

Pure substances have a … boiling point, and mixtures normally …

constant; do not

No slope on a phase graph means…

The changing heat is being used in changing phases

Slope on a phase graph means

Changing heat in the substance causes change in temperature.