First Elements on Periodic Table – Basic 6 Basic Technology Lesson Note (Second Term)

Learning Objectives

By the end of the lesson, pupils should be able to:

1. Explain what an atom is
2. Develop definition of elements
3. State the first ten elements with their symbols

Content

What is an Atom?

Definition: An atom is the smallest unit of matter that retains the properties of an element. It is the basic building block of all substances.

Structure of an Atom:

Three Main Subatomic Particles:

1. PROTONS 
   1. Positive charge (+1)
   2. Located in nucleus (center)
   3. Mass: 1 atomic mass unit (amu)
   4. Determines element identity
   5. Number of protons = Atomic number
2. NEUTRONS 
   1. No charge (neutral/0)
   2. Located in nucleus
   3. Mass: 1 amu
   4. Adds to atomic mass
   5. Isotopes have different neutron numbers
3. ELECTRONS 
   1. Negative charge (-1)
   2. Orbit nucleus in shells/energy levels
   3. Mass: negligible (1/1836 of proton)
   4. Involved in chemical bonding
   5. Determine chemical properties

Atomic Structure:

       Nucleus

    (Protons + Neutrons)

          ||

    Electron Shells

  (Electrons orbiting)

Key Concepts:

• Atoms are incredibly small (0.1 nanometers)
• Most of atom’s mass in nucleus
• Most of atom is empty space
• Same element = same number of protons
• Neutral atom: protons = electrons

What is an Element?

Definition: An element is a pure substance made of only one type of atom that cannot be broken down into simpler substances by chemical means.

Characteristics:

• Unique properties
• Identified by atomic number
• Unique name and symbol
• Cannot be separated chemically
• 118 confirmed elements exist

The Periodic Table

What it is:

• Organized chart of all elements
• Arranged by atomic number
• Shows chemical properties
• Created by Dmitri Mendeleev (1869)

Organization:

• Horizontal rows = Periods (7 periods)
• Vertical columns = Groups (18 groups)
• Elements in same group have similar properties
• Increasing atomic number left to right

Categories:

1. Metals – Left and center (shiny, conduct electricity, malleable)
2. Non-metals – Right side (dull, poor conductors, brittle)
3. Metalloids – Between (properties of both)

The First Ten Elements

1. HYDROGEN (H)

• Atomic Number: 1
• Symbol: H
• Type: Non-metal
• State: Gas
• Properties:
  1. Lightest element
  2. Colourless, odourless
  3. Highly flammable
  4. Most abundant in universe
• Uses:
  1. Rocket fuel
  2. Making ammonia (fertilizers)
  3. Fuel cells
  4. Found in water (H₂O)

2. HELIUM (He)

• Atomic Number: 2
• Symbol: He
• Type: Noble gas
• State: Gas
• Properties:
  1. Second lightest
  2. Inert (doesn’t react)
  3. Less dense than air
  4. Colourless, odourless
• Uses:
  1. Balloons and airships
  2. MRI machine cooling
  3. Deep-sea diving
  4. Leak detection

3. LITHIUM (Li)

• Atomic Number: 3
• Symbol: Li
• Type: Alkali metal
• State: Solid
• Properties:
  1. Soft, silvery-white
  2. Lightest metal
  3. Reacts with water
  4. Low density (floats on water)
• Uses:
  1. Rechargeable batteries (phones, laptops, electric cars)
  2. Mental health medication
  3. Ceramics and glass
  4. Lubricants

4. BERYLLIUM (Be)

• Atomic Number: 4
• Symbol: Be
• Type: Alkaline earth metal
• State: Solid
• Properties:
  1. Steel-gray color
  2. Lightweight but strong
  3. Toxic
  4. Good heat conductor
• Uses:
  1. Aerospace components
  2. X-ray equipment
  3. Copper alloys
  4. Nuclear reactors

5. BORON (B)

• Atomic Number: 5
• Symbol: B
• Type: Metalloid
• State: Solid
• Properties:
  1. Black or brown powder
  2. Very hard when crystalline
  3. Semi-conductor
  4. Multiple forms
• Uses:
  1. Glass (borosilicate)
  2. Detergents and bleaches
  3. Fiberglass
  4. Semiconductors

6. CARBON (C)

• Atomic Number: 6
• Symbol: C
• Type: Non-metal
• State: Solid
• Properties:
  1. Multiple forms (diamond, graphite, carbon fiber)
  2. Essential for life
  3. Forms millions of compounds
  4. Can form long chains
• Uses:
  1. Basis of organic chemistry and life
  2. Fuel (coal, charcoal)
  3. Pencil “lead” (graphite)
  4. Diamonds (jewelry, cutting)
  5. Carbon fiber (sports equipment)
  6. Steel production

7. NITROGEN (N)

• Atomic Number: 7
• Symbol: N
• Type: Non-metal
• State: Gas
• Properties:
  1. Colourless, odourless
  2. 78% of Earth’s atmosphere
  3. Relatively unreactive at room temp
  4. Essential for proteins and DNA
• Uses:
  1. Fertilizers
  2. Food preservation
  3. Liquid nitrogen (cooling)
  4. Making ammonia
  5. Inflating tires

8. OXYGEN (O)

9.Fluorine (F)

10.Neon (Ne)