Answer:
B, C
Explanation:
The atoms or ions with the valid Lewis dot structures are B and C.
In A;
The Lewis structure of the carbon is correct. Each of the four dots represent the four valence electrons.
The nitrogen with one dot on top, left and to the bottom and has a charge of minus 3 is wrong. For it to have a charge of -3 it must have 8 lewis dots ( two on the top, right, bottom and to the left)
The nitrogen with four dots (on top, right, bottom and to the left) is wrong.
In B;
An oxygen has two dots on top and bottom and one dot to the left and to the right. This is correct , the 6 dots represent the valence electrons of oxygen.
In C;
A carbon has two dots on top, right, bottom and to the left and a charge of plus four. This is correct because the charge indicates that it has gained four extra electrons so its valence electrons is now 8.
In D;
An oxygen has two dots on top, left and to the bottom and a charge of minus 2. This is wrong because the lewis dots are incomplete. Two dots are missing.
<span>Calcium crystal has a face center cubic (FCC) structure. For FCC structure,
relation between edge length (a) and radius (r) is
a = 2</span>√2 r
<span>Given: r = 180 pm
Therefore, a = 2</span>√2 180
<span> = 2 x 1.141 x 180
= 410.76 pm
</span><span>The length of the edge of the Ca unit cell is 410.76 pm.</span><span>
</span>
Answer:
Explanation:
The oxidation reduction reactions are called redox reaction. These reactions are take place by gaining or losing the electrons and oxidation state of elements are changed.
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
Consider the following reactions.
4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl
the oxidation state of copper is changed from +2 to +1 so copper get reduced.
CO + H₂O → CO₂ + H₂
the oxidation state of carbon is +2 on reactant side and on product side it becomes +4 so carbon get oxidized.
Na₂CO₃ + H₃PO₄ → Na₂HPO₄ + CO₂ + H₂O
The oxidation state of carbon on reactant side is +4. while on product side is also +4 so it neither oxidized nor reduced.
H₂S + 2NaOH → Na₂S + 2H₂O
The oxidation sate of sulfur is -2 on reactant side and in product side it is also -2 so it neither oxidized nor reduced.
Oxidizing agents:
Oxidizing agents oxidize the other elements and itself gets reduced.
Reducing agents:
Reducing agents reduced the other element are it self gets oxidized
Answer:
See explanation
Explanation:
The wittig reaction is an organic reaction in which an aldehyde or a ketone reacts with a phosphonium ylide to give an alkene. This phoshonium ylide that participates in the reaction is usually generated insitu in the system by reaction of an alky or aryl triphenylphosphonium halide salt with a base(sodium hydroxide is mostly used).
In this particular reaction 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride were reacted together in the presence of sodium hydroxide and the product with the structure shown in the answer was obtained as the major isomer produced in the reaction.
<span>Electron microscopes can magnify objects to 10,000,000x the smallest object that can be viewed is larger than an electron. Electron microscopes can improve the resolution that is achieved by light microscopes. Entire cells can be viewed and their components.</span>
