Answer: Option (C) is the correct answer.
Explanation:
An ion is defined as a specie which is formed when a neutral atoms tends to gain or lose an electron.
When a neutral atom gain an electron then it forms a negative ion whereas when a neutral atom tends to lose an electron then it forms a positive ion.
For example, a neutral fluorine atom on gaining an electron will form
ion. And, a sodium atom on losing an electron forms
ion.
When a group of atoms form ions then it tends to form polyatomic ions.
Thus, we can conclude that group of atoms that gains or loses electrons is called a polyatomic ion.
Answer:
Explanation:
Cu²⁺ + 2e⁻ → Cu ( copper gets reduced )
Cu → Cu²⁺ + 2e⁻ ( copper gets oxidized )
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.
Answer:
Reduction
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.
In given reaction fluorine gas gain two electron and form fluoride ions.
F₂(g) + 2e⁻ → 2F⁻(aq)
The given reaction is reduction because oxidation state is decreased from zero to -1.
Answer: D. Sublimation
Explanation: I just took the test.
Answer:
Solar eclipse
Explanation:
A solar eclipse occurs when a portion of the Earth is engulfed in a shadow cast by the Moon which fully or partially blocks sunlight. This occurs when the Sun, Moon and Earth are aligned. Such alignment coincides with a new moon indicating the Moon