The answer is D. I did that and i got it right.
An element is a pure substance that cannot be separated or divided into simpler substances by any method (physical or chemical). The four common elements in all the living organisms are carbon, oxygen, hydrogen, nitrogen.
Thus, the four elements that make up about 96 % of body matter are carbon, oxygen, hydrogen, nitrogen (c).
Answer
i’m in 7th grade but for this years science fair i did, “ how does temperature affect the elasticity of rubber bands”
Guide a growing plant through a maze.
8th Grade Science Plant Maze KiwiCo
Prove that plants really do seek out the light by setting up a simple or complex maze. This is a simple 8th grade science project with really cool results.
Blow out a candle with a balloon.
Blowing up a balloon with baking soda and vinegar is the classic acids and bases experiment. Take it a step further by experimenting with the carbon dioxide it produces. (Don’t be afraid of fire in the science
Stand on a pile of paper cups.
Combine physics and engineering and challenge 8th grade science students to create a paper cup structure that can support their weight. This is a cool project for aspiring architects.
hope this helps and have a wonderful day :)
Metals like sodium, potassium, magnesium, etc. are extracted by electrolysis of their chlorides in molten state.
These metals are not extracted by reduction of their oxides with carbon because:
Carbon has less affinity for oxygen than these metals
Carbon is a weaker reducing agent than these metals
These metals easily form oxides with oxygen, their oxides are very stable. Affinity to the oxygen is one the greatest of all elements.
Reducing agent is element or compound who loose electrons in chemical reaction. Sodium, potassium, calcium and magnesium are very strong reducing agents because they easily loose one or two valence electrons.
Electrolysis is a chemical methode that uses electric currents for chemical reactions.
More about reducing agent: brainly.com/question/7484765
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Answer:
Adiabatic temperature changes.
Explanation:
Temperature changes related to changes of pressure without external gain or loss of heat. If no heat is added or lost to the surroundings, then when an air parcel rises and expands, its temperature drops. Conversely, when the parcel is compressed, its temperature rises. So the term adiabatic, implies a change in temperature of the air parcel without gain or loss of heat from outside the air parcel.
