GENERAL CHEMISTRY

The International System of Units (SI) is a standardized system of measurement used globally, based on the metric system. It includes seven base units:

  1. Meter (length)

  2. Kilogram (mass)

  3. Second (time)

  4. Ampere (electric current)

  5. Kelvin (temperature)

  6. Mole (amount of substance)

  7. Candela (luminous intensity)

The metric system is a decimal-based system of measurement that includes units like meters, liters, and grams, facilitating easy conversion and calculation. The SI is the modern form of the metric system.

What is the metric conversion chart?

A metric conversion chart is a reference tool that shows the relationships between different metric units of measurement. It typically includes conversions for:

  • Length: millimeters (mm), centimeters (cm), meters (m), kilometers (km)

  • Mass: milligrams (mg), grams (g), kilograms (kg)

  • Volume: milliliters (mL), liters (L)

For example:

  • 1 km = 1,000 m

  • 1 m = 100 cm

  • 1 g = 1,000 mg

  • 1 L = 1,000 mL

This chart helps in converting between these units easily.

METRIC CONVERSION CHART

Prefix

Symbol

10n

exa

E

1018

peta

P

1015

tera

T

1012

Giga

G

109

mega

M

106

kilo

k

103

hecto

h

102

deca

da

101

base

(none)

100

deci

d

10-1

centi

c

10-2

milli

m

10-3

micro

µ

10-6

nano

n

10-9

pico

p

10-12

Metric prefix conversion refers to the process of changing the value of a measurement by using metric prefixes that denote specific powers of ten. Common metric prefixes include:

  • kilo- (k): 10³ (1,000)

  • mega- (M): 10⁶ (1,000,000)

  • giga- (G): 10⁹ (1,000,000,000)

  • milli- (m): 10⁻³ (0.001)

  • micro- (µ): 10⁻⁶ (0.000001)

  • nano- (n): 10⁻⁹ (0.000000001)

To convert, multiply, or divide by the appropriate power of ten based on the prefixes involved.

METRIC PREFIX CONVERSION

1.

2.

3.

4.

What is the accuracy and precision?

Accuracy refers to how close a measured value is to the true value.

Precision indicates the consistency of repeated measurements, regardless of whether they are close to the true value.

In summary:

  • Accuracy: Closeness to the true value.

  • Precision: Consistency of measurements.

PERCENTAGE OF ERROR

Percent error is the difference between the estimated value and the actual value in comparison to the actual value and is expressed as a percentage

Formula:

SIGNIFICANT NUMBERS

Significant Numbers:

Significant numbers (or significant figures) are the digits in a number that contribute to its precision. This includes all non-zero digits, any zeros between significant digits, and trailing zeros in a decimal number. For example, in 0.00456, there are three significant figures (4, 5, and 6).