Atomic Structure Fundamentals

Atomic Structure

• Atomic Models:
  • Rutherford's Atomic Model: Atom consists of a nucleus (protons and neutrons) and electrons orbiting around it.
  • Bohr's Atomic Model: Electrons occupy specific energy levels (shells) around the nucleus.
• Subatomic Particles:
  • Protons: Positive charge, present in the nucleus.
  • Neutrons: No charge, present in the nucleus.
  • Electrons: Negative charge, orbit around the nucleus.
• Atomic Number (Z): Number of protons in an atom's nucleus, unique to each element.
• Mass Number (A): Sum of protons and neutrons in an atom's nucleus.

Periodic Classification of Elements

• Mendeleev's Periodic Table: Arrangement of elements in a tabular form based on their atomic masses and chemical properties.
• Periods: Horizontal rows in the periodic table, representing elements with similar electronic configurations.
• Groups: Vertical columns in the periodic table, representing elements with similar chemical properties.
• Families of Elements:
  • Alkali Metals (Group 1): Highly reactive, lose one electron to form a cation.
  • Alkaline Earth Metals (Group 2): Less reactive, lose two electrons to form a cation.
  • Halogens (Group 17): Highly reactive, gain one electron to form an anion.
  • Noble Gases (Group 18): Unreactive, full outermost energy level.

Chemical Bonding

• Types of Chemical Bonds:
  • Ionic Bond: Formation of ions with opposite charges, resulting in a strong electrostatic attraction.
  • Covalent Bond: Sharing of electrons between atoms, resulting in a strong chemical bond.
• Electronegativity: The ability of an atom to attract electrons in a covalent bond.
• Polarity of Molecules: The uneven distribution of electrons in a covalent bond, resulting in a partial positive and negative charge.

Stoichiometry

• Mole Concept: A unit of measurement in chemistry, representing 6.022 x 10^23 particles (atoms, molecules, or ions).
• Molar Mass: The mass of one mole of a substance, expressed in grams per mole (g/mol).
• Empirical and Molecular Formula: Representation of a compound's composition, with empirical formula showing the simplest whole-number ratio of atoms and molecular formula showing the actual number of atoms.

States of Matter

• Solid: Particles are closely packed, with a fixed shape and volume.
• Liquid: Particles have some freedom of movement, with a fixed volume but variable shape.
• Gas: Particles have complete freedom of movement, with neither a fixed shape nor volume.
• Phase Changes: Changes between states of matter, such as melting, boiling, and condensation.

Atomic Structure

• Atom consists of a nucleus (protons and neutrons) and electrons orbiting around it.
• Rutherford's Atomic Model reveals the nucleus and electron orbitals.
• Bohr's Atomic Model explains electrons occupying specific energy levels (shells) around the nucleus.
• Protons have a positive charge and are present in the nucleus.
• Neutrons have no charge and are present in the nucleus.
• Electrons have a negative charge and orbit around the nucleus.

Atomic Number and Mass Number

• Atomic Number (Z) is the number of protons in an atom's nucleus, unique to each element.
• Mass Number (A) is the sum of protons and neutrons in an atom's nucleus.

Periodic Classification of Elements

• Mendeleev's Periodic Table arranges elements in a tabular form based on atomic masses and chemical properties.
• Periods are horizontal rows in the periodic table, representing elements with similar electronic configurations.
• Groups are vertical columns in the periodic table, representing elements with similar chemical properties.
• Alkali Metals (Group 1) are highly reactive, losing one electron to form a cation.
• Alkaline Earth Metals (Group 2) are less reactive, losing two electrons to form a cation.
• Halogens (Group 17) are highly reactive, gaining one electron to form an anion.
• Noble Gases (Group 18) are unreactive, having a full outermost energy level.

Chemical Bonding

• Ionic Bonds form when ions with opposite charges attract each other, resulting in a strong electrostatic attraction.
• Covalent Bonds form when atoms share electrons, resulting in a strong chemical bond.
• Electronegativity is the ability of an atom to attract electrons in a covalent bond.
• Polarity of Molecules occurs when electrons are unevenly distributed in a covalent bond, resulting in a partial positive and negative charge.

Stoichiometry

• A mole is a unit of measurement in chemistry, representing 6.022 x 10^23 particles (atoms, molecules, or ions).
• Molar Mass is the mass of one mole of a substance, expressed in grams per mole (g/mol).
• Empirical and Molecular Formula represent a compound's composition, with empirical formula showing the simplest whole-number ratio of atoms and molecular formula showing the actual number of atoms.

States of Matter

• Solids have particles that are closely packed, with a fixed shape and volume.
• Liquids have particles with some freedom of movement, with a fixed volume but variable shape.
• Gases have particles with complete freedom of movement, with neither a fixed shape nor volume.
• Phase Changes occur when substances change between states of matter, such as melting, boiling, and condensation.