Answer:
The carbon cycle
Or
Carbon moves from living things to the atmosphere. Each time you exhale, you are releasing carbon dioxide gas (CO2) into the atmosphere. Animals and plants get rid of carbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned.
The energy released from 1 gram of uranium is more than 1 million times greater than the energy released from 3 grams of coal is True.
<u>Explanation:</u>
Nuclear Fission is the process in which splitting of a nucleus takes place that releases free neutrons and lighter nuclei. The fission of heavy elements like "Uranium is highly exothermic" and releases "200 million eV" compared to the energy that is released by burning coal which gives a few eV.
In the given example, it is obvious that the energy released from 1 gram of uranium is more than that of the energy released from 3 grams of coal because the amount of energy released during nuclear fission is millions of times more efficient per mass than that of coal considering only
part of the original nuclei is converted to energy.
A measured value is expressed as a number along with a corresponding unit. The unit represents the dimension of the measured value.
For example:
- Length of an object can be expressed as, value + dimension. for example 10 m where 'm' is the dimension of length; meters
- Volume can be expressed as, value + dimension, for example, 10 L where L is the dimension of volume; Liters.
Ans C) Dimension
Answer is: n-octane.
Octane is the straight-chain alkane (an acyclic saturated hydrocarbon) with eight carbon atoms.
Carbons in octane have sp3 hybridization (carbon’s 2s and three 2p orbitals combine into four identical sp3 orbitals).
Orbitals in sp3 hybridization have a tetrahedral arrangement and form single (sigma) bonds.
Burning octane fuel is very fast chemical reaction, it happens in immediately.
Main products of the combustion of fossil fuels are carbon(IV) oxide and water.
Chemical reaction: C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O; ΔH = -5500 kJ/mol.