Chemistry 121Introduction

What is Chemistry

Chemistry is the study of matter and its changes

What is Matter?

Matter is anything that occupies space and has weight.

Examples of Matter

• Pens and pencils• Paper• Students• Desks• Cars• Airplanes

Is Air Matter?

Air would be matter if it takes up space and has weight.

Is Air Matter?

Air would be matter if it takes up space and has weight.Does it?

Is Air Matter?

Air would be matter if it takes up space and has weight.Does it?The space that air takes up is called the atmosphere.Does air have weight?

Is Air Matter?

Air would be matter if it takes up space and has weight.Does it?The space that air takes up is called the atmosphere.Does air have weight?Yes air does have weight, if not, then it would flow into outer space.

Is Air Matter?

Air would be matter if it takes up space and has weight.Does it?The space that air takes up is called the atmosphere.Does air have weight?Yes air does have weight, if not, then it would flow into outer space. One liter of air weighs 1.29 grams.

What are Changes?In the study of chemistry we talk about two different kinds of changes, physical and chemical

What are Changes?In the study of chemistry we talk about two different kinds of changes, physical and chemical

Physical change is a change to matter so that the identity is not altered; i.e. taste, smell….

What are Changes?In the study of chemistry we talk about two different kinds of changes, physical and chemical

Physical change is a change to matter so that the identity is not altered; i.e. taste, smell….

Chemical change is a change to matter so that its identity is changed; i.e. different smell, color, taste.

Examples of Physical Change• Tearing paper; starts out paper and ends as paper• Folding paper ; starts out paper and ends as

paper• Melting of ice ; starts out water and ends as

water• Evaporation of water ; starts out water and ends

as water

Examples of Chemical Change• Wood burning; starts out as wood ends up as

smoke and ashes, different smell and taste, right?

• Steel rusting; starts out as steel ends up as rust, different smell and taste

• Healing of a wound; starts out a blood ends up as scar tissue, different color, taste and smell

Matter Continued

Is everything matter?

Matter Continued

Is everything matter? No, not everything we can think of has weight and takes up space.

Matter Continued

Is everything matter? No, not everything we can think of has weight and takes up space.

For example personality!

Matter Continued

Is everything matter? No, not everything we can think of has weight and takes up space.

For example personality! One might argue that personality takes up the space of ones brain or person, but…

Matter Continued

Is everything matter? No, not everything we can think of has weight and takes up space.

For example personality! One might argue that personality takes up the space of ones brain or person, but…not all personable people are overweight. Thus personality does not have weight, and is therefore not matter.

Matter ContinuedHow about thought? Again we might argue that thought takes up the space of ones brain and your mother told you about heavy thoughts, but….

Matter ContinuedHow about thought? Again we might argue that thought takes up the space of ones brain and your mother told you about heavy thoughts, but….If you get on the bathroom scale and start having heavy thoughts, your weight does not go up!

Matter ContinuedHow about thought? Again we might argue that thought takes up the space of ones brain and your mother told you about heavy thoughts, but….If you get on the bathroom scale and start having heavy thoughts, your weight does not go up! That means thought is not matter, so if someone studies thought, they are not doing chemistry.

Examples of Chemistry• The study of why wood burns• The study of why cement does not burn• The study of why nails rust• The study of milk spoiling

These all fit the definition of chemistry since they deal with change and matter

History of Chemistry

Who were the first chemists?

History of ChemistryWho were the first chemists?

History of ChemistryWho were the first chemists?

Cavemen

History of ChemistryWhat kind of matter and changes did the cavemen study?

History of ChemistryWhat kind of matter and changes did the cavemen study? Fire and food!

Archeologists have found evidence of fire in caves and animal bones too. Cooking meat makes meat chewable. Chewing raw meet wears out ones jaw.

History of ChemistryThe next group that left archeological evidence of chemistry were the Egyptians. Their chemistry involved mummies, textile dyes, ink, paper and paints most of which can be found inside the pyramids.

History of ChemistryThe first group of people to leave written records of their chemistry were the Greeks. From Greek writings, we can see that the Greeks made observations, and created reasons for these observations, called hypothesis. They did not attempt to prove their hypothesis by experimentation, thus their chemistry efforts were philosophical in nature as opposed to science in nature.

History of ChemistryThe first group of chemists to test hypothesis with experiments were the alchemists. Alchemists were a group of Europeans that were trying to change matter in to different kinds of matter. For example, they were trying to change lead into gold. The major results of their experiments were to prove most of the Greek ideas of chemistry to be false and to show a clear distinction between science and philosophy.

History of ChemistryA major short coming of the Alchemists chemistry was irreproducible results, caused by lack of measurement understanding. For example, on day 1 mixing two kinds of matter produced black matter, while doing the same thing the next day produced red matter. The Alchemists were the first group of chemists to make observations, create hypothesis, and to test their hypothesis with experiments.

Modern ChemistryAntoine Lavoisier was the founder of modern chemistry by making careful measurements.

Modern ChemistryLavoisier’s careful measurements now made experiments reproducible. Chemists in other countries could now do the same experiment and get the same results. This now allowed chemists to prove a hypothesis to be correct by experimentation, thus leading to the discovery of theories and laws.

Modern Chemistry

• Law of Conservation of Mass• Atomic Theory

Lavoisier’s Theories and Laws

Classification of Matter

Matter

Homogeneous Heterogeneous

Substance Solution

Element Compound

Classification of Matter

Homogeneous matter looks the same everywhere with a microscope, but since we lack microscopes we will use our eyes and not our imagination. Heterogeneous matter does not look the same everywhere.

Homogeneous and Heterogeneous

Classification of MatterHomogeneous or Heterogeneous?

Wood Carpet Margarine Gold

Classification of MatterHomogeneous or Heterogeneous?

Wood Carpet Margarine GoldHeterogeneous

Classification of MatterHomogeneous or Heterogeneous?

Wood Carpet Margarine GoldHeterogeneous Heterogeneous

Classification of MatterHomogeneous or Heterogeneous?

Wood Carpet Margarine GoldHeterogeneous Heterogeneous Homogeneous

Classification of MatterHomogeneous or Heterogeneous?

Wood Carpet Margarine GoldHeterogeneous Heterogeneous Homogeneous Homogeneous

Classification of MatterSolution is a homogeneous random combination of two or more different types of matter.

For example a random amount of salt and water combined together produces a homogeneous mixture, called salt water. Random combination means some salt and some water.

Classification of MatterAny combination the produces a homogeneous result that is not randomly created is called a substance.

For example, combining two hydrogen atoms and one oxygen atom produces a compound of water, which is a substance. Or the combination of two oxygen atoms, gives a molecule of oxygen.

Classification of MatterHomogeneous matter created by the same atom is called and element. Exact combinations of different elements is called a compound.

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand•Sea water•Tap water•Steel•Antimony•Air•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water•Tap water•Steel•Antimony•Air•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water•Steel•Antimony•Air•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel•Antimony•Air•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony•Air•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water-Compound•Cement•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water-Compound•Cement-Heterogeneous•Wine

Classification of MatterLabel the following examples of matter as heterogeneous, solution, compound or element.•Sand-Heterogeneous•Sea water-Heterogeneous•Tap water-Solution•Steel-Solution•Antimony-Element•Air-Solution•Distilled water-Compound•Cement-Heterogeneous•Wine-Solution

The EndChapter #1