Chemistry Chapter 1: Matter and Properties

Study Notes

Definition of Matter

Matter is anything that has mass and occupies space.
Classified into two major categories: pure substances and mixtures.

Properties of Matter

Properties are distinguishing characteristics used to identify matter.
Types of properties include physical properties and chemical properties.

Physical Properties

Can be observed or measured without changing the chemical composition.
Examples:
- Color, shape, texture, state, odor, taste.

Density

Refers to the amount of matter in a given volume.
Dense objects have more matter packed into the same space than less dense objects.

Malleability

Ability of materials to be hammered or pressed into thin sheets.
Most metals are malleable due to strong particle connections with some movement.
Example: 30 grams of gold can cover 30 square meters.

Conductivity

Ability of a material to transfer heat or electricity.
Metals conduct heat, contrasted with materials like wood that do not.

Ductility

Ability of materials to be drawn into thin wires.
Gold is the most malleable and ductile metal; 1 ounce can be stretched into 80 kilometers of wire.
Other ductile materials include copper and aluminum.

Intensive vs. Extensive Properties

Intensive properties do not depend on quantity (e.g., ductility).
Extensive properties change with the amount present (e.g., mass, volume).

Physical Changes

Involves changes in appearance or state without altering chemical composition.
Example: Copper wire drawing changes shape but remains copper.
Boiling transforms liquid to vapor while retaining identity.

Chemical Properties

Describe behavior of matter in the presence of other substances or under conditions.
Key chemical properties include:
- Reactivity: Stability or reactivity based on conditions.
- Flammability: Whether a substance can burn.
- Toxicity: Adverse effects on living organisms, often measured with an LD50 rating (lethal dose for half exposed).

Chemical Changes

Occur when the chemical identity of a substance changes, indicating a chemical reaction.
Composition changes alongside physical and chemical properties.

Description

This quiz covers the fundamental concepts of matter, including its definition and classification into pure substances and mixtures. It focuses on the distinguishing physical and chemical properties of matter, essential for understanding the behavior of different materials.