Flashcards in Chapter 3 Deck (56):

0

## What is accuracy?

### how close the measured value is to the true value

1

## what is precision

### upon making repeated measurements, how close the measured values are to each other

2

## Which are you improving when you calibrate an instrument?

### accuracy

3

## Significant digits are used for what kind of values?

### measured

4

## What types of numbers do you disregard the sig digs?

###
counting

conversion factors

constants

5

## SI unit for mass

### kilogram kg

6

## what does second measure

### time

7

## What does m represent and measure

###
meter

length

8

## si temperature?

### kelvin

9

## difference between metric and SI

### kilogram vs. gram

10

## difference between mass and weight?

###
weight is a force that measures the pull of gravity on a given mass

mass is a measure of the amount of matter that an object contains

11

## How to convert celsius and kelvin?

###
K=C + 273

C=K-273

12

## Unit to measure the volume of a solid

### centimeter cubed

13

## units to measure the volume of a liquid

###
mL

L

14

## conversion factor for volume

###
1 cm cubed

___________

1mL

15

## Anything divided by itself equals

### 1

16

## What are the equations for density?

###
d=m/v

m=dv

v=m/d

17

## what is density

### the ratio of the mass of an object to its volume

18

## What kind of property is density and why?

### intensive - depends on composition not size

19

## What happens to the density of a material if the temperature goes up?

### density generally decreases

20

## what is a measurement

### a quantity that has both a number and a unit

21

## Why is it important to make correct measurements?

### measurements are fundamental to experimental sciences

22

## what happens in scientific notation

### a given number is written as the product of two numbers: a coefficient and 10 raised to a power

23

## What must happen to evaluate the accuracy of a measurement

### the measured value must be compared to the correct value

24

## what must happen to evaluate precision

### you must compare the values of two or more repeated measurements

25

## what is the accepted value

### the correct value based on reliable references

26

## what is the experimental value

### the value measured in the lab

27

## what is error

### the difference between the experimental value and the accepted value

28

## formula for error

### experimental value - accepted value

29

## what is percent error

### the absolute value of the error divided by the accepted value multiplied by 100%

30

## percent error equation

###
I error I

-------- X100

accepted value

31

## what are significant figures

### all of the digits that are known, plus a last digit that is estimated

32

## why must measurements always be reported to the correct number of significant digits?

### calculated answers often depend on the number of significant figures in the values used in the calculation

33

## In general, a calculated answer cannot be __________ than the least precise measurement from which it was calculated

### more precise

34

## 5 common SI units

###
meter

kilogram

kelvin

second

mole

35

## SI for amount of substance

### mole

36

## SI for luminous intensity

### candela

37

## SI for electric current

### ampere

38

## mole abbreviation

### mol

39

## candela abbreviation

### cd

40

## ampere abbreviation

### A

41

## what is volume

### the space occupied by any sample of matter

42

## what is temperature

### a measure of how cold or hot an object is

43

## what happens with heat

### it travels to the lower temperature area

44

## kelvin freezing and boiling points

### 273.15 and 373.15

45

## what is absolute zero

### zero on Kelvin

46

## what is energy

### the capacity to do work or to produce heat

47

## what are common units of energy

### joule and calorie

48

## which is si for energy

### joule

49

## what exactly is a calorie

### amount of heat it takes to raise the temperature of 1g of pure water by 1 degree C

50

## conversion factor joules to calories

###
1 J = 0.2390 cal

1 cal = 4.184 joules

51

## what is a conversion factor

### a ratio of equivalent measurements

52

## measurements in a conversion factor....

### the numerator is equal to the denominator

53

## when a measurement is multiplied by a conversion factor,

### the numerical value generally changes, but the actual size remains the same

54

## what is dimensional analysis

### a way to analyze and solve problems using the units, or dimensions, of the measurements

55