Chemistry Chapter 1: Matter & Measurement

What is Chemistry?

The scientific study of matter, its properties, and its behavior

Matter

• Anything that has mass and occupies space; everything that surrounds us

• Includes things we can and can’t see

• Can be classified according to composition and physical state

Composition

What is it made out of?

• Element

• Compound

• Mixture

Physical State

• Gas

• Liquid

• Solid

Properties

Characteristics used to describe matter, such as color, odor, and density

Behavior

The way matter reacts or changes under various conditions, including physical and chemical processes

What is the Importance of Chemistry?

• Central to understand other sciences and the connections between them

• Important practical applications (ex. energy, medicine, batteries in electronics) (chemical reactions are taking place)

• A way of explaining our material world

• What do the Properties of Matter relate to?

• The kinds of atoms (composition)

• The arrangement of atoms (structure) (how are they arranged?)

Atom

The building blocks of matter

Element

• A pure substance that consists of only 1 type of atom

• Cannot be decomposed into smaller substances

Compound

• Made of 2 or more different kinds of elements held together by special forces (ex. Water - H₂0)

• Constant ratio

• Pure substance

Mixture

• A physical combination/collection of 2 or more substances (elements and/or compounds)

• Not chemically bonded

• Not a pure substance; composition is never constant (ex. air in Albany is different from air in the Bronx)

Pure Substances

Elements & compounds

Diatomic Element

• Must exist as a 2-atom element, can’t exist on its own

• Hydrogen (H₂)

• Nitrogen (N₂)

• Oxygen (O₂)

• Fluorine (F₂)

• Chlorine (C₂)

• Bromine (Br₂)

• Iodine (I₂)

Scanning Tunneling Microscope

• Image surfaces at the atomic level

• 1986 Nobel Prize awarded to E. Ruska, G Binning, & H. Rohrer

How many elements are in the Periodic Table? How many are non-radioactive?

118 elements in the Periodic Table, 92 are non-radioactive (others are too unstable to exist in regular conditions, rapidly decay to other elements)

What are 2 ways the Periodic Table is organized?

Into blocks & columns