Skip to content
Dabour HubLEARN · PRACTICE · EXPLORESign inStudent

8.3.3The Periodic Table

The Big Bang Theory — Cambridge IGCSE Chemistry 0620 Revision Notes & Topical Questions

5 min read 5 parts Lesson 18 of 23 Unit quiz

📚 Cambridge IGCSE Chemistry 0620 Hub / Topical Revision
🩺
100% Curriculum Specification Match Lesson Doctor Verified
The only platform with 100% curriculum specification match and verified interactive question banks.
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
0%read

Part 1 of 5The Big Bang Model

1
The Universe is thought to have begun from a very small, hot and dense point about 13.8 billion years ago.
2
Space expanded outwards from that point, and as it expanded the Universe cooled.
3
The Universe is still expanding today, which is why distant galaxies are moving away from us.
4
Tracing this expansion back in time leads to the conclusion that the Universe began in a hot, dense state.

Part 2 of 5Evidence for the Big Bang

Red-shift
  • Red-shift Distant galaxies show a red-shift that increases with distance, consistent with an expanding Universe.
Cosmic microwave background
  • Cosmic microwave background Cosmic microwave background radiation, or CMBR, fills the Universe and is left over from its early stages.
Uniformity
  • Uniformity CMBR arrives from all directions at a similar intensity, which suggests the early Universe was nearly uniform.
Wavelength change
  • Wavelength change The CMBR was originally high-energy radiation, but its wavelength has increased as the Universe expanded.

Part 3 of 5About the CMBR

About the CMBR
Origin
  • Origin The radiation was released shortly after the start of the Universe, when it was hot and dense.
Detection
  • Detection It is detected as microwave radiation coming from all directions in space.
CMBR map
  • CMBR map The map shows very small temperature differences across the sky, showing that the early Universe was almost uniform.
Support
  • Support The Big Bang model explains the existence of the CMBR well, which is why it is widely accepted.

Part 4 of 5Worked Example

Question Describe and explain what the CMBR tells us about the early Universe.

  1. The CMBR is microwave radiation detected from all directions with a similar intensity.
  2. It was released shortly after the Universe began, when it was high-energy radiation with a short wavelength.
  3. Its wavelength has increased because the Universe has expanded, so it is now in the microwave range.

Answer The early Universe was very small, hot and energetic, and it has been expanding since.

Part 5 of 5Exam Checklist & Tips

8.3.3 – Key Points for the Exam

  • Big Bang The model in which the Universe expanded from a very hot, dense state about 13.8 billion years ago.
  • Cosmic microwave background radiation Microwave radiation that fills the Universe and was released shortly after its beginning.
  • Expansion of the Universe The growth of space itself, which makes galaxies move further apart.
  • Red-shift An increase in the wavelength of light from distant galaxies, showing that they are receding.
  • Uniform Having the same properties in all directions, as the early Universe appears to have been.

Common Mistakes

  • Describing the Big Bang as an explosion of matter into an existing empty space;
    • it is the expansion of space itself.
  • Saying that the CMBR is produced by stars today; it was released shortly after the Universe began.
  • Claiming that galaxies are moving away from a single centre;
    • galaxies move away from one another as space expands.

Last updated:

\n