THE SCIENCE OF CHEMISTRYChapter 1

1-1 WHAT IS CHEMISTRY? Chemical is any substance

with a definite composition. Can you come up with any

examples? Misconception: That

chemicals differ from substances and materials in nature.

1-1 WHAT IS CHEMISTRY?

What forms do chemicals come in? Physical state – arrangement of

particles in matter.

1-1 WHAT IS CHEMISTRY? Chemical Reaction – elements and/or

compounds rearrange to form new compounds

1-1 WHAT IS CHEMISTRY? Chemical reactions are classified by

energy being given off or absorbed during the process.

Exothermic reaction - energy is given off during the reaction (energy is released as bonds are broken)

Endothermic reaction – energy is absorbed during the reaction (more energy is needed to break bonds than to form the bonds on the product side)

1-2 WHAT IS MATTER? It is important to have a good definition of matter

when studying chemistry ……because chemistry is the study of matter and how it interacts.

Matter is anything that has mass and volume Mass – quantity of matter in an object (expressed in

grams or kilograms and use a balance to measure it)

Volume – amount of space an object occupies (expressed in L, mL or dm3 and use a graduated cylinder to measure liquids)

What is the difference between mass and weight?

1-2 WHAT IS MATTER? Qualitative vs Quantitative

measurement

1-2 WHAT IS MATTER? What can we measure and how can we

measure it?

1-2 WHAT IS MATTER?

Problem Solving and Dimensional Analysis

Find the equality between the two units Make a conversion factor (relates two

units of measure and is a way to change from one unit to another.)

Multiply given quantity by the conversion factor so the original unit cancels out

1-2 WHAT IS MATTER? Metric system is a system of measure

based on units of 10 and is used by scientists.

1-2 WHAT IS MATTER? Derived units – created from a

combination of base units. Volume of a regular solid = L x W x H Density = mass/volume Rate of speed = distance / time

1-2 WHAT IS MATTER?

Physical Property – describes measurable, physical attributes of the substance

Ex. Density, odor, color, melting point, boiling point

Chemical Property – refers to the ability of substances to forms new substances

Ex. Flammable, toxic, inert

1-2 WHAT IS MATTER?

Physical Change

generally a phase

change (substance

will still have same

chemical formula)

1-2 WHAT IS MATTER?

Chemical Change bonds between

atoms are broken and new bonds are

firmed to create new substances

with new chem/phys properties

Indicators of a Chemical Change

1.Color change

2.Gas is produced

3.Energy is released or absorbed

4.Precipitate is formed

1-3 WHAT IS THE NATURE OF MATTER?

Compounds – formed by 2 or more elements being bonded chemically

Elements – composed of only one type of atom

1-3 WHAT IS THE NATURE OF MATTER? Some elements have allotropic forms.

It is due to the way it is bonded and the number of atoms present.

Classification of

Matter