Unit 2: Physical and Chemical Properties, Math Foundations

Atoms

submicroscopic particles that are the fundamental building blocks of matter

Molecules

Atoms bonded together in specific geometrical arrangement

3 things properties of a molecule depend on:

1.) The type of atoms bonded (elements combining)

2.) The number of each type of atom

3.) Types of bonds (ionic, covalent, angles, lengths)

2 ways matter can be classified:

1.) Physical state (solid, liquid, gas)

2.) Composition

What are the three states of matter?

1.) Solids

2.) Liquids

3.) Gases

Describe the properties of a solid and its particles

• Definite Volume

• Definite Shape

• Particles are tightly packed in fixed locations

• Particles vibrate but cannot move past each other

Crystalline

• Atoms or molecules are in patterns with long-range, repeating order

• Ex: table salt and diamond (regular three-dimensional pattern)

Amorphous

• Atoms or molecules do not have any long-range order

• Ex: glass and plastic

Describe the properties of liquid and its particles

• Indefinite Shape (takes shape of container)

• Definite Volume

• Particles are in close contact, allowing them to move relative to each-other (reason why shape is indefinite)

Describe the properties of gas and its particles

• Indefinite Shape (takes shape of container)

• Indefinite Volume (takes volume of container)

• Particles are far apart, meaning they do not touch each other and can move freely

• Gas particles are compressible: can squeeze particles close together

Pure Substances

• Made up of one component

• Composition does not vary from one sample to another

  • ex: (water from other planet and water from earth remain the same)

• Components can either be:

  • Individual atoms (ex: helium)

  • Groups of atoms (ex: water, sodium chloride)

• What are the 2 types of pure substances and define them

• Elements —> CANNOT be broken down into simpler substances

  • Basic building blocks of matter

  • Composed of a single type of atom (ex: helium)

  • chemically reactive and combine with other elements to form compounds

• Compounds —> composed of 2 or more elements

  • ex: water (H2O) = hydrogen + oxygen

  • more common than pure elements

Define mixture

Matter that depends on how uniformly the components that make up the substance mix (Heterogenous and Homogenous)

Heterogenous Mixture

• composition varies from one part of the mixture to another

  • atoms and molecules separate

  • portions of a sample have different composition and properties

  • ex: salad, vegetable soup, sand and water — each sample will be different

Homogenous Mixture

• maintains same composition throughout

  • atoms and molecules mix uniformly

  • all portions of a sample have the same composition and properties

  • ex: salt water, stainless steel (salt diffuses into water)

Why do certain mixtures have to be separated differently?

Since every mixture has different components and properties that require a different method

Decanting

• Mixture of sand and water can be separated by carefully pouring off water into another container

  • Some water still present in the sand, less effective than filtration

Define Distillation and its process

• used to separate a homogenous mixture of liquids

  • mixture is heated to boil off the more volatile (easily vaporizable = lower boiling point) liquid

  • the volatile liquid evaporated is then re-condensed in the condenser which is later collected

Define Filtration and its process

• used to separate a mixture of an insoluble solid (cannot dissolve) and liquid

  • uses grates / filter paper to trap solid and allow for the liquid to be collected

  • ex: pouring pasta with water into grate to let hot water out and keep the pasta in

What is a physical change?

• Alters only physical state or appearance of matter (no change in identity / composition)

  • no change in composition

  • atoms or molecules do not change their identity

  • ex: water boiling —> water changed from liquid to gaseous state (gas remained composed of water molecules, H2O)

  • as the water heats, molecules at a very fast pace, however the molecular formula does not change

What is a chemical change?

• alters the composition of matter (changes appearance and identity)

  • atoms rearrange, transforming the original substances into different substances (change in composition)

  • ex: rusting of iron—iron atoms combine with oxygen molecules in air forming iron oxide (process called oxidation)

Examples of Physical Change:

1.) Dry Ice subliming (turning into gas)

• sublimation = solid turning into a gas

• Chemical composition unaltered, therefore Physical Change

2.) Sugar Dissolving

• dissolve = solid submerging and diffusing into mixture

• Chemical Composition Unaltered, therefore Physical Change

Examples of Chemical Changes:

1.) Propane Gas Burning

• Propane’s identity changes as it burns (with the help of oxygen)

• Chemical Composition altered, therefore chemical change

Define physical property and give examples

• Property that a substance displays without changing its composition

  • ex: color, taste, melting / boiling point, density, etc

Define Chemical Property and give examples

• Property that a substance displays only by changing its composition via a chemical change

  • often indicated by temperature, color change, or production of gas (not sublimation since change in composition occurs)

  • ex: flammability, corrosiveness, acidity, etc.

What are S.I. Units and its advantages?

• International System of Units

• 2 advantages over common units (feet-inches, pounds, ounces)

  • Universal: used by scientists all over the world

  • Based on multiples of 10 (metric system, easy to manipulate/use when moving decimals and adding / subtracting zeroes)

atoms

subatomic particles that are the fundamental building blocks of matter

molecules

atoms bonded together in specific geometrical arrangement

Carbon monoxide

colorless, odorless gas that binds irreversibly with hemoglobin (toxic, causes humans to lose red blood cells)

Carbon dioxide

colorless, odorless gas the binds reversibly with hemoglobin (non-toxic)

Water (H2O)

colorless, odorless, liquid

Hydrogen Peroxide (H202)

colorless, odorless liquid, bleaching agent, can burn skin, reactive

Properties of molecules (3)

1. Types of atoms bonded

2.# of each type of atom

3. Types of bonds

Classification of matter (2)

1. physical state

2. composition

Solids

Definite shape and volume

Liquids

Definite volume, no definite shape

Gasses

No definite shape or volume. Take the shape of their containers and can be compressed.

pure substance

only 1 component, composition doesn't vary, 2 types: elements and compounds

Elements

Can't be broken down into simpler substances, basic building blocks, single type of atom

Compounds

Composed of 2 or more elements

Mixtures

A combination of two or more substances that are not chemically combined

Hetergeneous Mixture

composition varies from one part of the mixture to another, atoms/molecules separate, NOT EVENLY MIXED

homogeneous mixture

Same composition throughout, atoms/molecules mixed uniformly, EVENLY MIXED

Decanting

Pouring liquid off the top when sediment has settled to the bottom of the container

Distillation

separating homogeneous mixtures by boiling off the more volatile liquid (lower boiling pt), volatile liquid re-condensed and becomes liquid

Filtration

used to separate a mixture of an insoluble solid and a liquid

physical change

alter only physical state or appearance of matter, NO CHANGE IN COMPOSTITON

Chemical change

alters the composition of matter, atoms rearrange, transforming the og substance into different substances

physical property

property that a substance displays without changing its composition

Chemical property

Property a substance displays only by changing its composition via a chemical change

SI Units

International System of Units: universal, based on multiples of 10

Length

meter (m)

Mass

kilogram (kg)

Volume

liter (L)

temperature

Kelvin (K)

Time

second (s)

Amount of substance

mole (mol)

kilo (k)

1000 times larger than base unit

deci (d)

10 times smaller than base unit

centi (c)

100 times smaller than base unit

mili (m)

1000 times smaller than base unit

micro (u)

1 million smaller than the base unit

_______meters = _______ kilometers

1000m = 1km

______meter = ____ centimeters

1m = 100cm

_____ meter = _____ millimeters

1m = 1000mm

______ meter = ____ micrometers

1m = 1000000um

_____ mililiter = ______ cubic centimeter(s)

1mL = 1cm_3

_____ liter = ____ milliliters

1L = 1000mL

_____ liter = ________ cubic centimeters

1L = 1000cm_3

____ kilogram = ____ grams

1 kg = 1000g

____ gram = ____ milligrams

1g = 1000mg

Weight

pull of gravity on a given mass- varies depending on location

____ second = _____ milliseconds

1s = 1000ms

___ k = ___ *C

0 k = -273 *C

Freezing point of water

0*C or 273k

Boiling point of water

100*C or 373k

From celsius to kelvin

k= *C+ 273

From kelvin to celsius

*C= k- 273

From fahrenheit to celsius

*C = (*F-32) / 1.8

From celsius to fahrenheit

*F= 1.8 (*C) + 32

Derived Units

combinations of different units ex: (m/s)

(m)

meter

(kg)

kilogram

(L)

liter

(k)

kelvin

(s)

second

(mol)

mole

Flammability

chemical property

Corrosiveness

chemical property

Acidity

chemical property

Taste

physical property

Color

physical property

melting point

physical property

boiling point

physical property

density

physical property

Malleability

physical property

Reactivity

chemical property