Stage 1 Chemistry: Introduction and Fundamentals Study Guide

Course Overview and Housekeeping Rules

• Required Materials for Every Lesson:

  • Writing materials: Notebooks, pens, and pencils.
  • Scientific calculator.
  • Textbook.
  • Laptop (must be fully charged).

• Homework and Study Expectations:

  • Time Commitment: Students are expected to complete $45$ to $60$ minutes of chemistry work every night.
  • Review: This time should be used to review learning and finalize note-taking from class.
  • Assessment: Work on ongoing assessment tasks and revise for upcoming tests and exams.
  • Nazareth Work Completion Policy: All work must be submitted by the deadline date; failure to do so will trigger the school's completion policy.

• Curriculum Context:

  • This course follows the Stage 1 Chemistry Subject Outline under the Learning and Assessment Plan (LAP) and CAP framework.

Defining Chemistry and Matter

• What is Chemistry?

  • Chemistry is formally defined as the study of the composition, structure, properties, and change of matter.

• What is Matter?

  • Matter is anything that possesses mass and takes up space.
  • It encompasses everything that can be perceived through the senses: everything you see, smell, and touch.

• Chemistry in Daily Life:

  • The air you breathe.
  • The food you consume.
  • The clothes you wear.
  • Medicines taken for health.
  • Transportation (the car or bus used to travel to school).
  • Technology: Notebooks, smartphones (iPhones), iPads, and flat-screen televisions.
  • Internal Biological Processes: Chemistry is constantly occurring inside the human body.

Chemistry as the Central Science

• The Hub of Science: Chemistry is termed the "Central Science" because its fundamental concepts are at the core of all other pure and applied sciences.
• Related Fields: Chemistry bridges gaps and provides the foundation for:
  • Astronomy.
  • Biology.
  • Physics.
  • Environmental Science.
  • Geology.
  • Nuclear Science.

Chemical Composition of the Human Body and Life

• Elemental Composition: Virtually everything, including human beings, is composed of elements found in the periodic table. The human body's composition by percentage of mass is as follows:

  • Oxygen ($O$): $65.0\%$
  • Carbon ($C$): $18.5\%$
  • Hydrogen ($H$): $9.5\%$
  • Nitrogen ($N$): $3.2\%$
  • Calcium ($Ca$): $1.5\%$
  • Phosphorus ($P$): $1.0\%$
  • Potassium ($K$): $0.4\%$
  • Sulfur ($S$): $0.3\%$
  • Sodium ($Na$): $0.2\%$
  • Chlorine ($Cl$): $0.2\%$
  • Magnesium ($Mg$): $0.1\%$

• Trace Elements: Elements making up less than $1.0\%$ of the body include:

  • Boron ($B$), Chromium ($Cr$), Cobalt ($Co$), Copper ($Cu$), Fluorine ($F$), Iodine ($I$), Iron ($Fe$), Manganese ($Mn$), Molybdenum ($Mo$), Selenium ($Se$), Silicon ($Si$), Tin ($Sn$), Vanadium ($V$), and Zinc ($Zn$).

• Chemical Indicators of Life:

  • DNA (Deoxyribonucleic Acid): Consists of phosphate groups, sugars (deoxyribose), and nitrogenous bases organized into Purines and Pyrimidines. It features a $3'$ end and a $5'$ end.
  • Cellular Respiration: The process of converting nutrients into energy.
    • Standard Equation: $\text{Sugar} + \text{Oxygen} \rightarrow \text{Carbon Dioxide} + \text{Water} + \text{Energy}$
    • Molecular Equation: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$

• Glycolysis Pathway (The Detail of Respiration):

  • Glucose is converted to Glucose $6$-phosphate via Hexokinase (utilizing $ATP \rightarrow ADP$).
  • Phosphoglucose isomerase converts this to Fructose $6$-phosphate.
  • Phosphofructokinase converts it to Fructose $1,6$-bisphosphate (utilizing $ATP \rightarrow ADP$).
  • Aldolase splits it into Dihydroxyacetone phosphate and Glyceraldehyde $3$-phosphate.
  • Glyceraldehyde $3$-phosphate dehydrogenase facilitates the move toward $1,3$-Bisphosphoglycerate.
  • Phosphoglycerate kinase produces $ATP$ while creating $3$-Phosphoglycerate.
  • Phosphoglycerate mutase creates $2$-Phosphoglycerate.
  • Enolase creates Phosphoenolpyruvate ($PEP$), releasing $H_2O$.
  • Pyruvate kinase produces the final Pyruvate molecule and $ATP$.

Branches of Chemistry

• Organic Chemistry: The study of chemical compounds consisting primarily of Carbon ($C$) and Hydrogen ($H$).
  • Examples: Medicines, drugs, detergents, and plastics.
• Inorganic Chemistry: The study of chemical compounds that do NOT contain $C-H$ bonds.
  • Examples: Pure elements, minerals, and oxides.
• Physical Chemistry: The application of the techniques and theories of Physics to chemical systems.
  • Examples: Electroplating, combustion, and fluorescence.
• Analytical Chemistry: The study of the separation, identification, and quantification of the chemical components of matter.
  • Examples: Quality testing of water, crime scene investigations, and blood examinations.
• Biochemistry: The study of chemical processes that occur within living organisms.
  • Examples: Protein synthesis, the composition of DNA, and the structure of hormones.

Fundamentals of Atomic Structure

• Subatomic Particles:

  • Protons ($P$): Positively charged ($+$, located in the nucleus.
  • Neutrons ($N$): Neutral (no charge), located in the nucleus.
  • Electrons ($E$): Negatively charged ($-$), orbit around the nucleus. They are approximately $1800 \times$ smaller than protons and neutrons.

• Charge Balance:

  • Atoms are electrically NEUTRAL.
  • Therefore, the number of negatively charged electrons must equal the number of positively charged protons ($\text{Number of Protons} = \text{Number of Electrons}$).

Electron Shell Configuration

• Arrangement: Electrons are arranged in specific electron "shells."

• Motion: Electrons orbit the nucleus in random motion within their designated shells.

• Filling Rules:

  • Shells fill in order from the one closest to the nucleus to the one furthest away.
  • Attraction: There is a greater attraction between the negative electrons and the positive protons closer to the nucleus.
  • Energy: Electrons in higher (outer) shells possess significantly more energy than those in lower (inner) shells.

• Shell Capacities:

  • $1\text{st}$ Shell: Maximum of $2$ electrons.
  • $2\text{nd}$ Shell: Maximum of $8$ electrons.
  • $3\text{rd}$ Shell: Maximum of $18$ electrons.
  • $4\text{th}$ Shell: Maximum of $32$ electrons.
  • Outermost Shell (Valence Shell): Maximum of $8$ electrons (except for the first shell, which is stable with $2$).

• Example (Sodium - $Na$):

  • Sodium has $11$ protons and $11$ electrons.
  • Configuration: $2, 8, 1$.

The Periodic Table Structure

• Atomic Number:

  • Defines the identity of the element by the number of protons.
  • It is always the smaller number on the periodic table entry.
  • Since atoms are neutral, this also indicates the number of electrons.

• Mass Number / Relative Atomic Mass:

  • Calculated as $\text{Number of Protons} + \text{Number of Neutrons}$.
  • Protons and neutrons have roughly the same weight.
  • The mass of an electron is approximately $9.1 \times 10^{-31}\,kg$. Because it is so small, it is considered "massless" relative to nucleons and is not included in the atomic mass calculation.

• Groups (Vertical Columns):

  • There are $18$ groups.
  • Elements in a group share the same number of valence electrons (outer shell electrons).
  • Rule for Groups $13-18$: If there is more than one digit in the group number, take the second digit to find the valence electrons (e.g., Group $14$ has $4$ valence electrons).
  • Transition Metals: The valence electron rule does not apply directly to transition metals (Groups $3-12$).
  • Exception (Helium): Helium is in Group $18$ because its properties align with noble gases, even though it only has $2$ valence electrons.

• Periods (Horizontal Rows):

  • There are $7$ periods.
  • The period number indicates the number of occupied electron shells for the elements in that row.

Isotopes and Nuclear Notation

• Definition: Isotopes are atoms of the same element that have the same atomic number (number of protons) but a different number of neutrons.

• Result: They have different mass numbers.

• Nuclear Notation Setup:

  • The mass number ($A$) is written at the top left of the chemical symbol.
  • The atomic number ($Z$) is written at the bottom left of the chemical symbol.
  • Note: This is inverted compared to some layouts found on general periodic tables.

• Example: Hydrogen Isotopes:

  • Hydrogen ($^1H$): $1$ Proton, $0$ Neutrons ($99.98\%$ abundance).
  • Deuterium ($^2H$): $1$ Proton, $1$ Neutron ($0.02\%$ abundance).
  • Tritium ($^3H$): $1$ Proton, $2$ Neutrons (radioactive, trace amounts).

• Example: Chlorine and Iron Isotopes:

  • $^{35}Cl$: $17$ Protons, $18$ Neutrons ($75.58\%$).
  • $^{37}Cl$: $17$ Protons, $20$ Neutrons ($24.22\%$).
  • $^{56}Fe$: $26$ Protons, $30$ Neutrons ($91.75\%$).

Ion Formation and Trends

• Definition: An ion is a charged atom formed when an atom gains or loses electrons.

• Stability (The Octet Rule): An atom is most stable when it has a full valence shell of $8$ electrons (or $2$ for the first shell). Atoms will gain or lose electrons to reach this state.

• Ionic Formation Process (Example: Sodium):

  • Sodium ($Na$) is in Group $1$ and has $1$ valence electron.
  • To be stable, it could gain $7$ electrons or lose $1$. Losing $1$ is easier.
  • After losing $1$ electron, it has $11$ protons (+$ आत्मनिर्भर) and 10$electrons ($-).\n * **Net Charge:** 1+.\n * **Notation:** Electron configurations for ions must be in square brackets with the charge indicated: [2, 8]^+.\n\n* **Periodic Trends for Ionic Charge:**\n * **Metals:** Tend to **lose** electrons to form positive ions (**cations**).\n * Group 1$: Lose$1$electron$(\rightarrow +1).\n * Group 2$: Lose$2$electrons$(\rightarrow +2).\n * **Non-metals:** Tend to **gain** electrons to form negative ions (**anions**).\n * Group 6$: Gain$2$electrons$(\rightarrow -2).\n * Group 7$: Gain$1$electron$(\rightarrow -1).\n * **Stability Exception:** Hydrogen and Helium are stable with only 2$$ electrons in their single shell.