In physical geography<span>, a </span>dune<span> is a </span>hill<span> of loose </span>sand<span> built by </span>wind<span> or the flow of water.</span><span> Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a </span>slack<span>. A "dune field" is an area covered by extensive sand dunes. Dunes occur, for example, in some </span>deserts<span> and along some coasts.</span>
The thermodynamic barrier that must be overcome before products are formed in spontaneous reaction is activation energy.
The activation energy is the maximum amount of extra energy that is required by a reacting molecules to get converted into product. It is the minimum energy that is required or needed to activate or energize molecules or atoms.
It is needed in the reaction so that reactants can move together and overcome forces of repulsion and start bond breaking.
Reactant is the substance that takes part in and that undergoes change during a reaction.
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Answer:
Feline Immunodeficiency Virus
Explanation:
Uracil pairs with adenine in RNA base
The gas form of water is water vapor.
