Answer:
λ = 0.38 ×10⁻⁹ m
Explanation:
Given data:
Wavelength of xray = ?
Frequency of xray = 7.8 ×10¹⁷ Hz
Solution:
Formula:
Speed of light = wavelength × frequency
speed of light = 3×10⁸ m/s
Now we will put the values in formula.
3×10⁸ m/s = λ × 7.8 ×10¹⁷ Hz
λ = 3×10⁸ m/s / 7.8 ×10¹⁷ Hz
Hz = s⁻¹
λ = 3×10⁸ m/s / 7.8 ×10¹⁷s⁻¹
λ = 0.38 ×10⁻⁹ m
Answer:
A. a new substance is being produced.
Explanation:
The bubbles most likely indicates that a new substance is being produced by this reaction. In essence, we describe this sort of change as chemical change.
In a chemical change, new substances are usually produced. They are accompanied by the evolution or absorption of energy.
The reaction of Zinc with a strong acid to produce bubbles on the surface of the metal indicates a chemical change and the formation of a new kind of substance.
Take for example, let zinc reacts with hydrocholoric acid, HCl;
Zn + 2HCl → ZnCl₂ + H₂
Since Zn is higher than Hydrogen in the activity series, it will displace it from HCl and liberate hydrogen gas as a product. This will cause the bubbles observed in the reaction.
This is a chemical change and new products have been formed.
B and D are wrong because they are both physical changes.
C is wrong because no information about such is provided by the problem statement.
So, when a piece of zinc metal combines with a strong acid, a new kind of substance is produced.
The balanced redox reaction, if it occurs in acidic solution, is
5C₂O₄²⁻(aq) + 2MnO₄⁻(aq) + 16H⁺-----> 10CO₂(g) + 2Mn²⁺(aq) + 8H₂O(l)
<h3>What are redox reaction?</h3>
Redox reactions are those in which loss and again of electrons occur.
To balance the redox reaction, we must first break the whole reaction into half equations;
Oxidation half equation
Reduction half equation
Now combine both the reactions
Thus, the coefficient of H₂C₂O₄ is 5 and that of water is 8.
Learn more about redox reactions
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1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1
Primero realizas la configuración electrónica que es la que te puse allá arriba.
Después miras el nivel en que termina, puede ser 1, 2, 3, 4 etc.
Entonces como el último número de la configuración electrónica es 4, entonces ese es el nivel
Y los electrones de el último nivel son los de Valencia
4s2, 4p1 sumas 2+1 que son los electrones que se encuentran en el último nivel.
por eso hay 3 electrones de valencia.
