Applied Science I, IDT 103 Module Objectives

APPLIED SCIENCE I, IDT 103 MODULE OBJECTIVES

1. Understanding Fundamentals of Science

a. Basic Terminologies

• Atoms: The smallest particles of matter consisting of sub-particles: protons, neutrons (located in the nucleus), and electrons (surrounding the nucleus in orbitals).

  1. Protons: Positively charged sub-particles in the nucleus of the atom; they have mass.

  2. Neutrons: Sub-particles with no charge located in the nucleus; they also have mass.

  3. Electrons: Negatively charged sub-particles with negligible mass that orbit the nucleus, held in place by electrostatic attraction.

Exercise (Page 5)

1. Explain why Sodium (Na) is very reactive, but Neon (Ne) is not.

2. Illustrate the reaction between Na and Fluorine (F).

3. Why is the Periodic Table so named?

Nucleons

• Definition: Sub-particles in the nucleus of an atom, consisting of both protons and neutrons.

Mass Number (A)

• The sum total of nucleons in the nucleus (protons + neutrons).

Atomic Number (Z)

• The number of protons in an atom.

Ions

• Atoms that have lost or gained electrons.

  • Positive ions (CATIONS) are formed by losing electrons.

  • Negative ions (ANIONS) are formed by gaining electrons.

Electronegativity

• The tendency of an atom to gain an electron.

Isotope

• Atoms with the same atomic number but different mass numbers.

  • Example: Carbon-14 and Carbon-12, where all have the same number of protons but differ in the number of neutrons.

Element

• A pure substance consisting entirely of one type of atom that cannot be broken down into simpler substances by chemical means.

Molecule

• A group of two or more atoms bonded together that retains the chemical properties of that substance.

  • Example: O2 (homonuclear) and H2O (heteronuclear).

The Periodic Table

• Arranged in increasing order of atomic number. Elements in the same period (horizontal row) share similar properties, while those in the same group (vertical column) have similar chemical properties.

• The table aids in identifying trends in atomic size, melting points, and reactivity.

Chemical Compounds & Solutions

• Chemical Compounds: Substances formed when two or more elements are chemically bonded.

  • Example: Water (H2O), Hydrogen Peroxide (H2O2).

• Solutions: Homogeneous mixtures of solute and solvent (e.g., NaCl in water).

2. Types of Chemical Bonding

Atomic Bonding (Chemical Bonding)

• Chemical Bond: A lasting attraction between atoms, ions, or molecules resulting in the formation of compounds.

  • Bonding can occur due to electrostatic forces (ionic bonds) or electron sharing (covalent bonds).

• Valence: The number of electrons in the outer shell of an atom that can participate in bonding.

  • An atom with a valence of zero is classified as an inert or noble gas (non-reactive).

2.1. Primary Bonds

1. Ionic Bonding: Formed through the attraction between positive and negative ions.

   • Formation involves the transfer of electrons from one atom to another (e.g., Na + Cl → NaCl).

   • Properties of Ionic Compounds: Hard, brittle, conduct electricity when melted or dissolved in water, with high melting points.

2. Covalent Bonding: Involves the sharing of electron pairs between non-metal atoms.

   • Covalent compounds are formed and displayed as molecules.

   • Properties: They tend to have lower melting and boiling points compared to ionic compounds and do not conduct electricity.

   • Examples of covalent bonds include H-H and O=O bonds.

3. Metallic Bonding: Arises from the attraction between conduction electrons and positively charged metal ions.

   • Properties: Ductility, malleability, and electrical conductivity.

2.2. Secondary Bonds

• Hydrogen Bonding: Result of a dipole interaction where a hydrogen atom is partially positive and interacts with negatively charged portions of other molecules.

• Van der Waals Forces: Weak intermolecular forces from dipole interactions, impacting properties such as mechanical strength.

3. SI Units of Physical Quantities

Common SI Units:

• Force: Newton (N)

  • Defined as the force that causes a mass of 1 kg to accelerate at 1 m/s².

• Power: Watt (W)

  • The work done when a force of 1 N moves a distance of 1 m in 1 second.

• Weight: Newton (N) (same as force).

• Work: Joules (J)

  • Work done when a force of 1 N moves through 1 m.

• Electric Current: Ampere (A)

  • One coulomb of charge flows per second.

• Temperature: Kelvin (K), Celsius (°C).

• Volume: Cubic Centimeter (cm³), Metre (m).

4. Comparison Between Plant and Animal Cells

• **Common Organelles:

  1. Nucleus: Controls cellular activities and contains genetic material.

  2. Cytoplasm: Medium that contains organelles.

  3. Cytoskeleton: Structural framework of the cell, determining shape.

  4. Cell membrane: Semi-permeable membrane controlling substance movement.

Non-Common Organelles:

• Centrioles: Found in animal cells, assist in cell division.

• Vacuoles: Larger in plant cells, provide structural support and storage.

• Chloroplasts: Present in plant cells for photosynthesis; contains chlorophyll.

• Cellulose Cell Wall: A protective structure in plant cells.

Summary of Differences:

5. Characteristics of Materials for Interior Works

• Elements: Classified as metals, non-metals, and semi-metals according to their position in the periodic table.

5.1. Metals

• Properties: Malleable, ductile, sonorous, excellent conductors of heat and electricity.

• Noble Metals: E.g., Gold (Au), Copper (Cu), Silver (Ag), Mercury (Hg).

• Base Metals: Not pure, e.g., Iron (Fe) and Aluminum (Al).

• Ferrous Metals: Contain iron; are magnetic.

• Non-Ferrous Metals: Do not contain iron; have desirable properties such as low weight and corrosion resistance.

5.2. Ferrous Metals Manufacturing Processes:

• Iron Ore: Basic raw material obtained from the earth; often contains impurities.

• Coal or Coke: Reducing agents in the blast furnace.

• Limestone: Combines with impurities to form slag.

• Gangue: The worthless material left in iron ore extraction.

5.3. Types of Iron:

1. Wrought Iron: Pure iron, worked with hammers; used for railings and ornamental purposes.

2. Cast Iron: Contains 2-4% carbon; used for engine blocks and wear-resistant structures.

3. Steel: Less than 2% carbon; stronger than cast iron; used in construction and manufacturing.

   • Types of Steel:

     • Mild Steel: Less than 0.25% carbon; used in automobiles.

     • Medium-Carbon Steel: 0.25-0.6% carbon; used for higher-stressed components.

     • High-Carbon Steel: 0.6-1.4% carbon; ideal for cutting tools and high-strength wire.

     • Stainless Steel: Corrosion-resistant; contains chromium.

5.4. Physical Properties of Metals vs Non-metals:

5.5. Chemical Properties of Metals:

• Metals can lose electrons easily, forming cations.

• Reactive metals form oxides with oxygen and react with water and acids.

• Noble metals remain unaffected by air and dilute acids.

5.6. Uses of Metals:

• Aluminum: Cooking utensils.

• Gold: Jewelry.

• Copper: Wiring.

• Silver: Jewelry and photography.

• Zinc: Corrosion protection.

• Tin: Alloy production.

5.7. Plastics:

• Definition: Chains of molecular units called polymers, containing primarily carbon and hydrogen.

• Usage: Food protection, electrical insulation, construction materials, etc.

5.8. Types of Plastics:

1. Thermosetting Plastics: Cannot be remelted after setting.

2. Thermoplastics: Can be reheated and reshaped.

5.9. Wood Chemical Composition:

• Major constituents include lignin (20-40%), cellulose (40-60%), and hemicellulose (10%).

• Minor constituents include extractives and proteins that offer pest resistance and other functional properties.

5.10. Monomers and Polymers:

• Monomers: Small molecular units that connect to form polymers through condensation.

• Polymerization can occur through: 1) Addition reactions, 2) Condensation reactions (where water is released).

5.11. Organic Chemistry:

• Aliphatic Compounds: Straight or branched; categorized into saturated (alkanes) and unsaturated (alkenes, alkynes).

• Aromatic Compounds: Contain conjugated rings such as benzene, less reactive than alkenes.

5.12. Reactions of Benzene:

• Electrophilic aromatic substitution maintains the stability of the aromatic system, resulting in products like chlorobenzene and alkylated benzene.

6. Corrosion of Metals and Its Prevention

6.1. Corrosion Process:

• Iron and Steel Conversion: React with moisture and oxygen to form rust (Fe2O3.xH2O).

• Salt from seawater accelerates corrosion.

6.2. Preventing Rusting:

1. Coating: Greasing, painting, electroplating, and galvanizing.

2. Sacrificial Protection: Using a more reactive metal to prevent rust.

6.3. Alloying:**

• Alloys combine metals to achieve better properties; examples include stainless steel, bronze, and brass.

6.4. Common Alloys:**

6.5. Differences between Bronze and Brass:

• Bronze, a copper-tin alloy, has superior properties than brass, a copper-zinc alloy.

• Bronze is harder and more resistant to corrosion than brass.

Assignment Examples:

• Classify Elements: Metals, non-metals, and semi-metals.

• Properties of Bonds: Discuss conditions of corrosion and prevention principles.

• Explain Alloys and Their Components: Specific uses for bronze, brass, and stainless steel.