Nitrogen cycle : Denitrification :: carbon cycle : -----Nitrogen cycle : Denitrification :: carbon cycle : -----
carbon dioxide into carbohydrates
highly reactive with other elements
Answers
Answer:
Explanation:
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✠Question
➤ Differentiate between :-
Physical change and Chemical change.
Compound and Mixtures.
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✠Answers
➽ Physical change :-
In a physical change, only physical properties such as colour, physical state, density volume, etc. change; chemical properties remain unchanged.
No new substance is formed in a physical change.
Very little or no energy in the form of heat, light or sound is usually absorbed or given out in a physical change.
A physical change is a temporary change.
The original form of substance can be regained by simple physical methods.
A physical change in reversible.
➽ Chemical change :-
In a chemical change, the chemical composition and chemical properties undergo a change.
A new substance is formed in a chemical change.
A chemical change is always accompanied by absorption or evaluation of energy.
A chemical change is a permanent change.
Original substance cannot be obtained by simple physical methods.
A chemical change is irreversible.
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➽ Compounds :-
Compound are formed as a result of chemical reactions between two or more elements of compounds.
The components of a compound are always present in a definite ratio by mass.
The properties of a compound are entirely different from its constituents.
Compounds are always homogeneous in nature.
Compound formation is accompanied by absorption or evolution of light, heat or electrical energy.
Melting and boiling points of a compound are usually sharp and fixed.
The constituents of a compound can be separated by chemical methods.
➽ Mixtures :-
Mixtures are formed by simply mixing two or more constituents. There are no chemical reactions between the constituents.
The components of a mixture may be present in any ratio.
The properties of a mixture are same as those of constituents.
Mixtures are usually heterogeneous (except in solutions).
Heat, light or electrical energy may not be evolved or absorbed during the formation of a mixture.
Melting and boiling points of a mixture are usually not sharp and fixed.
The components of a mixture can be easily separated by physical methods.
Answer:
The short term cycling of carbon begins with carbon dioxide (CO2) in the atmosphere.
The production of food energy by land plants.
Through photosynthesis, the inorganic carbon in carbon dioxide plus water and energy from sunlight is transformed into organic carbon (food) (Figure above) with oxygen given off as a waste product. The chemical equation for photosynthesis is below:
Plants and animals engage in the reverse of photosynthesis, which is respiration. In respiration, animals use oxygen to convert the organic carbon in sugar into food energy they can use. Plants also go through respiration and consume some of the sugars they produce.
The chemical reaction for respiration is:
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + useable energy
Photosynthesis and respiration are a gas exchange process. In photosynthesis, CO2 is converted to O2 and in respiration, O2 is converted to CO2.
Do plants create energy? It is important to remember that plants do not create energy. They change the energy from sunlight into chemical energy that plants and animals can use as food (Figure below).
The carbon cycle shows where a carbon atom might be found. The black numbers indicate how much carbon is stored in various reservoirs, in billions of tons (“GtC” stands for gigatons of carbon). The purple numbers indicate how much carbon moves between reservoirs each year. The sediments, as defined in this diagram, do not include the ~70 million GtC of carbonate rock and kerogen.