Chapter 1 Chemistry the

science of matter

By QBP Cristina A. Rmz.

Vocabulary

• Chemistry• Matter• Mass• Property• Scientific model• Qualitative• Quantitative• Substance• Mixture

• Physical change

• Physical property

• Solution• Alloy• Solute• Solvent • Aqueos

solution• Element• Compund• formula

Chemistry

• Is the science that investigates and explains the structure and properties of matter

Matter

• Is anything that takes up space and has mass

Mass

• Is the measure of the amount of matter that an object contains

• What isn´t matter ?

• Figure 1.1 page 4

The structure of matter

• Refers to its composition

The properties of matter

• Describe the characteristics and behavior of matter including the changes that matter undrgoes.

• Figure 1.2 , 1.3 and 1.4 page 5

The macroscopic level of matter

• Matter that is large enough to be seen is called macroscopic , so all of your observations in chemistry and everywhere else start from this perspective

• The macroscopic world is the one you touch, feel, smell, taste and see.

• Figure 1.5 page 7

The submicroscopic level of matter

• The submicroscopic level view gives you a glimpse into the world of atoms

• Its a world so small that you cannot see it even with the most powerful light microscope

• Figure 1.6

Using models in chemistry

• Page 8

• Figure 1.7

• Figure 1.8 page 9

Using models in chemistry

• Scientists use many types of models to represent things that are hard to visualize

A scientific model

• Is a thinking device that helps you understand and explain macroscopic observations

In the field

• Read page 12 and 13

Classifying matter

• Classification by composition

• What is it made of ?

• Example sucrose is composed of the elements carbon, hydrogen and oxigen

• A QUALITATIVE observation is one that can be made without measurement

• After qualitative analysis the next question is how much of the elements is present

• For sucrose is: 100.0 g of sucrose contains 42.1 g of carbon, 51.4 g of oxigen and 6.5 g of hydrogen

• A QUANTITATIVE observation is one that uses measurement

Pure substance or a mixture?

• In terms of purity

• PURE: made up of only one kind of matter

• MIXTURE: of different kinds of matter

Pure substances

• Figure 1.10

• Means that every bit of the matter being examined is the same substance

• A SUBSTANCE is matter with the same fixed composition and properties

• Sucrose, sand (silicon dioxide)

Mixtures

• Figure 1.11 page 15

• A combination of two or more substances in which the basic identity of each substance is not changed

• Figure 1.12 page 16

Everyday Chemistry

• Read page 17. You are what you eat.

The separation of mixtures into substances

• Mixtures cab be separated into its components by physical processes (phyisical: the process does not change the identity of a substance).

• How colud you separate a mixture of sugar and sand?

By using physical changes

• A phyisical change is a change in matter that does not involve a change in the identity of the substance (boiling, freezing, melting, evaporating, dissolving, and crystallizing)

Physical properties

• Are characteristics of a sample of matter that can be observed or measured without any change in its identity

• Examples: state (solid, liquid, gas), color, solubility, boiling point, melting point, etc.

• Look at figure 1.13 page 20

Types of mixtures

• HETEROGENEOUS mixtures• Hetero means different

• So, its one that does not have a uniform composition and in which the individual substances remain distinct

• The components exist as distinct regions called phases = you can see the different substances in the mixture

• HOMOGENEOUS: homo means alike, are the same throughout, they are called solution (might appear to be one pure substance)

• Solutions are solids, liquids or gases

• Alloys are solid solutions, table 1.1 page 23

Solutions

• Are composed bay two components: solute and solvent

• Water + sugar: water = solvent (dissolves the solute) and sugar = solute (being dissolve).

• Aqueous solution = when the solvent is water

• Look at page 26

Substances: pure matter

• ELEMENTS: the building blocks, the simplest form of matter (figure 1.16)

• 117 elements. Figure 1.17 page 27

• COMPOUNDS: made of two or more substances

• The properties of the compound are different from the properties of the elements that compose the compound

• Table 1.3 page 30

• Look at page 29

Formulas of compounds

• Is a combination of the chemical symbols that show what elements make up a compound and the number of atoms of each element

• Table 1.3 page 30 second column

• Session 1.1 assessment page 31

Properties and changes of matter

• PHYSICAL PROPERTIES are those that dont involve changes in composition

PHYSICAL QUALITATIVE PROPERTIES

• Such as: solid, hard…

• PHYSICAL QUANTITATIVE PROPERTIES

• Such as: melting point, density, mass…

• Figure 1.20 page 32

States of matter

• Solid• Liquid• Gas• Plasma

• Read: states of matter page 23• Figure 1.21 page 33

Change of state

• Read changes of state page 33

• Fusion• Solidification• Boiling• Condensation• Liquefaction• sublimation