Review for Chemistry Test Flashcards
What the the steps to the Big Bang
1) Started with a Singularity
Infinitely dense point
Contained all matter and energy
2) Singularity Expanded
Protons, neutrons and electrons formed
Hydrogen and Helium atoms formed
3) Giant space clouds called nebulas formed
Giant clouds of H and He
4) Stars & Galaxies are formed under the force of gravity
5) Solar systems are formed (we are here today)
Explain how the Red Shift helps prove the Big Bang Theory
Light from distant galaxies: When we observe light from galaxies far away, it appears to be stretched out, shifting toward the red end of the spectrum. This is called redshift.
Doppler Effect: Just like the sound of a moving ambulance changes pitch (Doppler effect), light waves from galaxies moving away from us stretch, increasing their wavelength and shifting them toward red.
Expanding Universe: The redshift suggests that galaxies are moving away from us. The farther a galaxy is, the faster it is receding. This is evidence that the universe itself is expanding.
Hubble’s Law: In the 1920s, Edwin Hubble discovered a correlation between redshift and distance. More distant galaxies have a greater redshift, implying that the universe is expanding uniformly in all directions.
Big Bang Implication: If galaxies are all moving away from each other, it suggests that, in the past, everything must have been much closer together. This aligns with the idea that the universe began from a very hot, dense state, supporting the Big Bang theory.
Explain how the CMB (Cosmic Radiation Background) supports the Big Bang Theory
Old Light: The CMB is leftover radiation from the Big Bang, created when the universe was very hot. At first, this radiation was in the form of gamma rays (high-energy light).
Cooling Down: As the universe expanded, this radiation stretched out and cooled, turning from gamma rays into microwave radiation, which we can detect today.
Evenly Spread: The CMB is spread out evenly across the sky, showing that the early universe was very hot and uniform.
Like a Heater: The CMB matches what we’d expect from a very hot object cooling down, just like the Big Bang theory predicts.
Stretched Light: The light from the Big Bang has been stretched (redshifted) into microwaves because the universe has expanded over time.
Big Bang Prediction: Scientists predicted this kind of radiation before it was discovered, based on the Big Bang model.
Fill in the blanks
The Beginning
1) About 13.7 Billion years ago the matter in the singularity __________________________. This matter cooled and began to quickly move apart. It was not really an ‘explosion’ but an expansion like a _________________________________.
The universe expanded rapidly as a whole _______________________. (The universe is still expanding today as a result of the Big Bang).
2) First Particles
Matter was created in the form of tiny particles, our old friends ________________, _________________, and _______________. It is too hot for larger particles to form (eg. __________ and _____________________). This happened after 0.001 sec.
3) First Atoms
After ________________ years, the universe is much cooler and atoms start to form….. the particles gathered to form atoms of ________________________________.
4) First Gases
After 1 million years Hydrogen and Helium gathered in _________________________.
5) Gas Nebulas
After 300 million years, the gases clumped into giant ____________________ called ___________________.
6) Stars and Galaxies
After ____________________ years, nebula clumped together under the force of gravity to form ___________ and __________________.
7) Our Solar System
__________________ years ago a _______________________ came together to form our Solar System with the Sun (a star) at its centre.
The ________________________________ - Solar System formed out of a nebula which collapsed under its own ________________..
