Excretion
Extracting metals
Excretion is the process in which your body removes the toxic waste products which have been generated in the cells of your body. The human excretory system plays a important role in eliminating toxic substances from your body.The kidney filters toxic waste products such as Urea from your blood to form urine, while the lungs remove carbon dioxide, the skin also helps in excreting waste products through sweat.
What we learned:
Excretion removes waste products to maintain a healthy body.
The kidneys, lungs, skin, and liver are major excretory organs.
Extracting metals is the process of obtaining metals from their ores. Ores are rocks which metals can be extracted from. The method used to extract a metal depends on its placement in the reactivity series.
Electrolysis (For Highly Reactive Metals)
Used for metals like aluminum, sodium, and potassium.
The metal is extracted by passing electricity through its molten ore.
Example: Aluminum is extracted from bauxite (Al₂O₃) using electrolysis.
Reduction with Carbon (For Less Reactive Metals)
Used for metals like iron, zinc, and lead.
The metal oxide is heated with carbon (coke or charcoal), which removes oxygen.
Example: Iron is extracted from hematite (Fe₂O₃) in a blast furnace.
Direct Heating (For Least Reactive Metals)
Used for metals like gold and silver, which occur naturally in pure form.
These metals do not need to be extracted from ores, just separated from impurities.
What is a galaxy:
A galaxy is a massive collection of stars, gas, dust, and dark matter held together by gravity
A galaxy consists of:
Stars-usually thousands of millions of them.
Planetary systems-Astronomers think that mst stars have planetary systems.
stellar dust and gas- from stars that have exploded, or left over from the format of Universe.
The universe is everything that exists. All the stars comits, asteroids, meteors and everything else make up the universe.
Our solar system is surrounded by gas and dust in the Kuiper belt and the Oort cloud.