Genral Chemistry I lecture notes, Lecture notes of Chemistry

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Chapter 1

Introduction

Matter & Measurement

CHEMISTRY

The Central Science

Dr. Öğr. Üyesi G. Gülenay Hacıosmanoğlu

Chapter 1

Introduction:

Matter and

Measurement

Matter And Measurement Matter Anything that has mass and takes up space.

Matter And Measurement Methods of Classification

• State of Matter
• Composition of Matter

Matter And Measurement

Classification of Matter

Based on Composition

Matter And Measurement

Classification of Matter

Pure Substances and Mixtures

• Atoms consist only of one type of element.
• Molecules can consist of more than one type of element:

• Molecules can have only one type of atom: an element
• Molecules can have more than one type of atom: a compound

• If more than one atom, element, or compound are found together, then the substance is a mixture

Matter And Measurement

Classification of Matter

Elements: If a pure substance cannot be decomposed into something else, then the substance is an element.

• There are currently 118 named elements.
• Each element is given a unique chemical symbol (H, Ca)
• Only five elements make up 90% of the Earth’s crust by mass.
• Only three elements make up 90% of the human body by mass.

Matter And Measurement Compounds Compounds have a definite composition : the relative number of atoms of each element in the compound is the same in any sample. Classification of Matter

Matter And Measurement

Classification of Matter

Based on Composition

Matter And Measurement

Properties of Matter

➢ Intensive properties

➢ Extensive properties

Matter And Measurement Types of Changes

• Physical changes: changes in matter that

do not change the composition of a

substance.

• Examples: changes of state, temperature,

and volume.

• Chemical changes: result in new

substances.

• Examples: combustion, oxidation, and

decomposition.

Matter And Measurement Changes in State of Matter

• Converting between the three states of matter is a physical change.
• Ex: When ice melts or water evaporates, there are still 2 H atoms and 1 O atom in each molecule.

Matter And Measurement

Separation of Mixtures

• Mixtures can be separated based on

physical properties of the components of

the mixture.

Some methods:

• filtration
• distillation
• chromatography

Matter And Measurement Filtration: Separates solid substances from liquids and solutions.