Elements emit colours when heated because electrons in atoms can have only certain allowed energies.Heating an atom excites its electrons and they jump to higher energy levels. When the electrons return to lower energy levels, they emit energy in the form of light. Every element has a different number of electrons and a different set of energy levels. Thus, each element emits its own set of colours. See, for example, mercury and neon above. Those colours are as distinctive to each element as fingerprints are to people.
Our understanding of the universe has changed a lot over time!
Ptolemy
He improved on Aristotle's theory which was that the earth was the center of the universe also known as geocentric.
Nicolaus Copernicus
Copernicus had a theory that the sun was the center of our solar system. This is also known as heliocentric.
Tycho Brahe
His work supported the idea that the Earth orbited the sun.
Brahe hired Kepler, another astronomer to work with him.
How has our understanding of the universe changed over time?
Aristotle
Johannes Kepler
Galileo
Isaac Newton
Edmund Halley
Edwin Hubble
By Isamilla & Nelleke
The Hubble space telescope was named after Edwin Hubble.
He had three laws of motion.
He hypothosized that the nebulae were their own galaxies.
<span>He imagined the earth at the </span>
center of the universe with the sun, the moon, the stars and the planets orbiting it in perfect circles.
Newton put Kepler and Galileo's ideas together and discovered that the reason that things fall on the ground is the same reason that planets orbit around the sun.
He made a telescope that could magnify
up to 30 times.
<span>He discovered that Copernicus' theory </span>
was true. "We're not the center of the universe."
He found out that the planets orbit the
sun in ellipses (oval shapes).
He explained how the tides were made by the moon.
He figured out that the speed of the planets depend on the sun.
Halley discovered a comet. It was discovered in 1705. It will come around again in 2061
The comet Halley comes every 75 - 76 years
384–322 BCE
90 AD – 168 AD
1473 – 1543
1546 – 1601
1571 – 1630
1564 – 1642
1642 – 1727
1656 – 1742
1889 – 1953
Celestial Sphere
<span>It's an invisible sphere around the earth
</span>
Answer:
An absolute monarchy is one in which the king is God's representative on Earth, giving him absolute power that's free from all restraints. He created a centralized state that gave him complete power over the French government. King Louis XIV was an absolute monarch because he answered only to God.
Answer:
A gene is the physical and functional unit of heredity. Genes are made up of DNA. DNA are made up of 4 letters. those 4 letters "write the code in you".<u>Some</u> genes act as instructions to make molecules called proteins.
