11.1 The overarching concepts in chemistry

• Atoms consist of a nucleus containing protons and neutrons, surrounded by electrons in shells.
• What organizes elements based on their atomic structure?

  Periodic table
• Match the organization of the periodic table with its feature:

  Groups ↔️ Vertical columns

  Periods ↔️ Horizontal rows
• Chemical bonding is the formation of bonds between atoms.
• Ionic bonds are formed by the sharing of electrons between atoms.

  False
• What type of electron transfer occurs in ionic bonds?

  Complete transfer
• The three states of matter are solid, liquid, and gas.
• Gases have a low density compared to solids and liquids.
• Steps to balancing a chemical equation

  1️⃣ Count the number of atoms of each element

  2️⃣ Adjust the coefficients to match the number of atoms

  3️⃣ Verify that the equation is balanced
• What is the purpose of balancing chemical equations?

  Conserve mass and charge
• Steps to balance the equation 2H₂ + O₂ → 2H₂O

  1️⃣ Write the unbalanced equation

  2️⃣ Adjust the coefficients

  3️⃣ Check the number of atoms on both sides
• Match the reaction type with its example:

  Exothermic ↔️ Combustion reactions

  Endothermic ↔️ Photosynthesis
• Atoms are composed of a nucleus containing protons and neutrons
• Match the organization of the periodic table with its feature:

  Groups ↔️ Vertical columns

  Periods ↔️ Horizontal rows
• In ionic bonds, electrons are completely transferred from a metal to a nonmetal
• Gases have a high density compared to solids and liquids.

  False
• What effect does increasing temperature have on the rate of reaction?

  Increases the rate
• Exothermic reactions release more energy than they absorb.


  True
• Catalysts are consumed in a chemical reaction.

  False
• Match the property with the correct chemical substance:

  Release H⁺ in water ↔️ Acids

  Release OH⁻ in water ↔️ Bases
• What type of reactions are central to electrochemistry?

  Redox reactions
• The number of protons in the nucleus determines the element.
• Features of the periodic table

  1️⃣ Elements arranged by atomic number

  2️⃣ Organized into groups (vertical) and periods (horizontal)

  3️⃣ Chemical properties determined by position
• Ionic bonds are formed by the transfer of electrons between atoms.
• Match the state of matter with its particle arrangement:

  Solid ↔️ Closely packed in fixed positions

  Liquid ↔️ Closely packed but can move around

  Gas ↔️ Widely spaced and move randomly
• Gases have a low density compared to solids.

  True
• Steps for balancing chemical equations

  1️⃣ Ensure the number of atoms of each element is the same on both sides

  2️⃣ Adjust coefficients to conserve mass and charge

  3️⃣ Check that the balanced equation is correct
• Photosynthesis is an example of an endothermic reaction.


  True
• Exothermic reactions release energy to the surroundings.


  True
• Match the reaction type with its energy change

  Exothermic ↔️ Releases energy

  Endothermic ↔️ Absorbs energy
• Endothermic reactions absorb more energy than they release.


  True
• What is chemical equilibrium?

  Forward and reverse reactions occur at the same rate
• Which principle predicts how changes in temperature, pressure, and concentration affect equilibrium?

  Le Chatelier's principle
• Acids turn blue litmus paper red.


  True
• What is the pH range for acidic solutions?

  0 to less than 7
• What are the fundamental building blocks of all matter?

  Atoms
• The number of protons in the nucleus determines the element.


  True
• The composition of atoms includes protons, neutrons, and electrons.
• What does the organization of the periodic table allow us to predict about elements?

  Chemical properties
• What are the two main types of chemical bonds?

  Ionic and covalent