<span><span>4.2×1022</span>NA</span><span> N_{A} is the avagadro number</span>
Answer:
No reaction
Explanation:
Single-displacement reaction is the chemical reaction in which one metal which has higher negative redox potential replaces the another from it's salt solution.
Thus, Cu cannot replaces zine from its salt as it is less reactive than zince.
However, zinc can replace copper from its salt as:

Answer: The three main rock types are igneous, metamorphic and sedimentary.
The three processes that change one rock to another are crystallization, metamorphism, and erosion and sedimentation.
Any rock can transform into any other rock by passing through one or more of these processes. This creates the rock cycle.
Explanation:
<h2>
Answer:
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Nitrogen forms many thousands of organic compounds. Most of the known varieties may be regarded as derived from ammonia, hydrogen cyanide, cyanogen, and nitrous or nitric acid. The amines, amino acids, and amides, for example, are derived from or closely related to ammonia.
<h3>
Explanation:
</h3>
A carbohydrate has only Carbon, Hydrogen and Oxygen, with the hydrogen and oxygen in the ratio 2:1.
Examples are glucose C6H12O6 and table sugar C12H22O11
A protein is made of amino acids. Amino acids have an amino group which is −NH2.
So without nitrogen atoms the compound cannot be a protein.
Nucleic acids are organic compounds that contain carbon, hydrogen, nitrogen but they also contains phosphorus and oxygen. They are made of smaller units called nucleotides.
So;
Simple Amines are the class of organic compounds that only contains Carbon, Hydrogen and Nitrogen.
He knew he was in the desert when he saw the dust blowing and a cactus. /// He was trying to desert the field in which was dangerous.