Chemistry test

Lesson 1: Chemistry Basics

Matter

• Anything that has mass and takes up space

Pure Substances

• Matter that contains only one kind of particle

• A particle can be a single type of atom or compound

Elements

• A pure substance that cannot be broken down into simpler parts by chemical methods

• Elements are different types of atoms (118 known types)

Compounds

• A pure substance made of two or more different elements that are chemically combined

Mixtures

• Matter that contains more than one kind of particle

Mechanical Mixtures

• When two or more substances are mixed together, and you can see more than one substance

• Example: Separations

Solutions

• Made up of more than one substance, but you can only see one substance

• May involve a solute and a solvent

• Example:

• Solute: Sugar

• Solvent: Water

Lesson 2: Physical Properties of Matter

Definition

• Characteristics of a substance that can be observed and measured without changing its chemical identity

Examples of Physical Properties

✔ Length

✔ Color

✔ Density

✔ Mass

✔ Elasticity

✔ Pressure

✔ Volume

✔ Luster (a glow of reflected light)

Qualitative Physical Properties

• Can be observed and described without measuring

• Examples:

• State: Solid, liquid, or gas

• Opacity: Transparency

• Malleability: Ability to bend or shape

• Ductility: Ability to be drawn into wire

• Luster: How shiny

• Color, odor, texture, taste

Quantitative Physical Properties

• Involves measurement and numerical values

Examples:

• Melting Point: Temperature at which a substance melts

• Boiling Point: Temperature at which a substance boils

• Viscosity: Resistance to flow

• Hardness: Ability of a solid to scratch another material

Lesson 3: Chemical Properties and Changes

Chemical Properties of Matter

• The ability of a substance to react with another substance to form one or more new substances

Four Major Categories of Chemical Properties

✔ Reactivity – How a substance reacts with water, oxygen, or acids

✔ Combustibility – The ability of a substance to burn in air

✔ Stability – How easily a substance decomposes or breaks down

✔ Toxicity – The ability of a substance to cause harm to animals or plants

Physical Changes

• A change in matter where no new substances are formed

• Unexpected changes may appear, but the particles remain the same

Chemical Changes

• A reaction where one or more new substances are formed

• Atoms of the original compounds are rearranged to form new compounds