Answer:
35.453 atomic mass units
You can use Phet (Atomic masses, Elements and more) for Chemistry
The change of the statue of liberty from copper to green is an example of a chemical change.
<h3>Physical and chemical change</h3>
A physical change does not involve the formation of new substances and the composition of the substance does not change. However, in a chemical change, a new substance is formed and the composition of the substance changes.
The statement that reflect a chemical change is;
- The Statue of Liberty’s metal tarnishes from copper to green.
Learn more about physical and chemical change: brainly.com/question/13316655
Answer:
11
Explanation:
The atomic number = number of protons. The mass number (23) = sum of number of neutrons and protons. Since you know the mass number is 23 and it has 12 neutrons, 23-12 gives you 11 protons, so its atomic number is 11.
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Answer:
Electrones de valencia.
Explanation:
¡Hola!
En este caso, dado en química se conocen las estructuras de Lewis como representaciones gráficas de como los elementos están enlazados entre sí, debemos tener en cuenta que estos enlaces se forman entre los electrones de valenciam, los cuales son utilizados para su representación. Se sabe que los electrones de valencia son representados con puntos alrededor del elemento a través de puntos que se unen entre sí y son el número de electrons en la capa más externa de los elementos en cuestión; por ejemplo, cloro tiene 7 electrones de valencia, azufre tiene 6, hidrogeno 1, carbono 4 y así sucesivamente.
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Answer:
See Explanation
Explanation:
1) Let us recall that;
Mass number = number of protons + number of neutrons
Where;
Number of protons = ?
Number of neutrons =20
Mass number =39
Number of protons = mass number - number of neutrons
Mass of protons =39 - 20= 19 protons
2) Atomic number = 13
Number of neutrons =14
Then the mass number =13 +14 =27
The symbol of the element is 27X13
The number of protons= the number of electrons =13
The atomic number is the same as the proton number =13
