Atomic Structure and Elements Quiz

Lesson Objectives

• Atoms are described by the Rutherford model
• Electrons have a negative charge
• Protons have a positive charge
• Neutrons have no charge
• Electrostatic attraction between positive and negative charges holds atoms together
• Purity describes the amount of a specific chemical in a mixture

Atoms

• All matter is made of tiny particles called atoms
• Atoms are made of protons, neutrons, and electrons

Atomic Structure

• Atoms have a nucleus containing protons and neutrons
• Electrons orbit the nucleus

Elements

• Elements are substances made of only one type of atom
• Examples include carbon, gold, and silver

Different Types of Atoms

• 94 types occur naturally
• 24 types created in labs

Matter

• Anything that can be touched physically is matter
• All matter is made up of atoms

Pure Products

• Scientists often need to have pure products in chemical reactions
• Impurities can affect the effectiveness and safety of a product
• Some reactions have only one product
• Other reactions produce multiple products
• Products may be mixed with unused reactants

Examples of Pure Products Reactions

• Magnesium + oxygen → magnesium oxide
• Silver nitrate + sodium chloride → sodium nitrate + silver chloride
• Sulfuric acid + sodium hydroxide → sodium sulfate + water
• Barium chloride + sodium sulfate → barium sulfate + sodium chloride
• Lead nitrate + potassium iodide → potassium nitrate + lead iodide
• Copper carbonate + hydrochloric acid → copper chloride + water + carbon dioxide

Seawater

• Seawater contains water and various salts
• Sodium chloride is a common salt in seawater
• Evaporating seawater can extract sodium chloride
• Seawater contains 3.5% of salt
• About 68% of seawater salt is sodium chloride

Purity

• Pure elements contain only one type of atom
• Gold purity is measured in carats
• 24-carat gold is pure gold (100% gold)
• 18-carat gold is 75% gold and 25% other metals
• The photograph displays different carat gold samples; colors change gradually from coppery to yellow-gold as gold content increases

Atoms: The Building Blocks of Matter

• Atoms are the basic units of matter that are too small to be seen
• Even a large amount of atoms in space occupy a tiny amount of space

Diamonds

• Diamonds are made of a carbon element
• The arrangement of atoms makes a diamond transparent and clear
• Other elements mixed with the carbon element affect its color

Silver

• Silver items are often marked to show their purity
• 925 silver is 92.5% pure silver

Atomic Theory - A Brief History

• This section presents a brief history of atomic theory.