Atomic Structure Quiz

Atomic Structure

• Atomic model: protons, neutrons, and electrons
  • Protons: positive charge, found in nucleus
  • Neutrons: no charge, found in nucleus
  • Electrons: negative charge, found in energy levels (shells)
• Atomic number (Z): number of protons in an atom's nucleus
• Mass number (A): number of protons and neutrons in an atom's nucleus
• Electron configuration: arrangement of electrons in energy levels
  • Valence electrons: electrons in outermost energy level
  • Core electrons: electrons in inner energy levels

Periodic Trends

• Periodic table: arrangement of elements by atomic number and recurring properties
• Periodic trends: changes in properties across a period or group
  • Atomic radius: decreases from left to right, increases down a group
  • Electronegativity: increases from left to right, decreases down a group
  • Ionization energy: increases from left to right, decreases down a group
  • Electronegativity and ionization energy: related to atomic radius

Phase Changes

• Phase changes: transitions between solid, liquid, and gas states
  • Melting point: temperature at which a solid changes to a liquid
  • Boiling point: temperature at which a liquid changes to a gas
  • Latent heat: energy required for phase change
  • Heat of fusion: energy required for melting
  • Heat of vaporization: energy required for boiling

Chemical Reactions

• Chemical reaction: process in which reactants form products
  • Reactants: substances that undergo change
  • Products: substances formed during reaction
  • Chemical equation: representation of reaction using chemical formulas
  • Law of conservation of mass: matter cannot be created or destroyed
• Types of chemical reactions:
  • Synthesis: two or more reactants form a single product
  • Decomposition: single reactant breaks down into two or more products
  • Single displacement: one element displaces another
  • Combustion: reaction involving oxygen and heat

Elemental Properties

• Metals:
  • Typically shiny and malleable
  • Good conductors of heat and electricity
  • Lose electrons to form cations
• Nonmetals:
  • Typically dull and brittle
  • Poor conductors of heat and electricity
  • Gain electrons to form anions
• Metalloids:
  • Exhibit some properties of metals and nonmetals
  • Semiconductors: intermediate conductivity
• Representative elements:
  • Group 1 (alkali metals): highly reactive, lose one electron
  • Group 2 (alkaline earth metals): less reactive, lose two electrons
  • Group 17 (halogens): highly reactive, gain one electron
  • Group 18 (noble gases): unreactive, full outer energy level

Atomic Structure

• Protons have a positive charge and are found in the nucleus of an atom.
• Neutrons have no charge and are found in the nucleus of an atom.
• Electrons have a negative charge and are found in energy levels (shells) around the nucleus.
• The atomic number (Z) is the number of protons in an atom's nucleus.
• The mass number (A) is the number of protons and neutrons in an atom's nucleus.
• Electron configuration is the arrangement of electrons in energy levels.
• Valence electrons are electrons in the outermost energy level.
• Core electrons are electrons in inner energy levels.

Periodic Trends

• The periodic table is an arrangement of elements by atomic number and recurring properties.
• Periodic trends are changes in properties across a period or group.
• Atomic radius decreases from left to right and increases down a group.
• Electronegativity increases from left to right and decreases down a group.
• Ionization energy increases from left to right and decreases down a group.
• Electronegativity and ionization energy are related to atomic radius.

Phase Changes

• Phase changes are transitions between solid, liquid, and gas states.
• Melting point is the temperature at which a solid changes to a liquid.
• Boiling point is the temperature at which a liquid changes to a gas.
• Latent heat is the energy required for a phase change.
• Heat of fusion is the energy required for melting.
• Heat of vaporization is the energy required for boiling.

Chemical Reactions

• Chemical reactions are processes in which reactants form products.
• Reactants are substances that undergo change.
• Products are substances formed during a reaction.
• Chemical equations represent reactions using chemical formulas.
• The law of conservation of mass states that matter cannot be created or destroyed.
• Synthesis reactions involve two or more reactants forming a single product.
• Decomposition reactions involve a single reactant breaking down into two or more products.
• Single displacement reactions involve one element displacing another.
• Combustion reactions involve oxygen and heat.

Elemental Properties

• Metals are typically shiny and malleable, good conductors of heat and electricity, and lose electrons to form cations.
• Nonmetals are typically dull and brittle, poor conductors of heat and electricity, and gain electrons to form anions.
• Metalloids exhibit some properties of metals and nonmetals, are semiconductors, and have intermediate conductivity.
• Representative elements include:
  • Alkali metals (Group 1), which are highly reactive and lose one electron.
  • Alkaline earth metals (Group 2), which are less reactive and lose two electrons.
  • Halogens (Group 17), which are highly reactive and gain one electron.
  • Noble gases (Group 18), which are unreactive and have a full outer energy level.