Answer:
-) Lewis structure: See the figure 1
-) Oxidation number of As = +5
-) Oxidation number of O = -2
Explanation:
The first step is to calculate the <u>total amount of electrons</u>, for As we will have 5 electrons, for all the oxygens we will have 24 electrons (6 electrons for each atom) and finally we will have 3 more due to the charge (-3), so in total we will have: 5+24+3= 32 electrons.
In the lewis structure, we will have as <u>central atom</u> "As" then we have to put the oxygens around the central atom. In this case, As is an <u>exception of the octet rule</u>, in this structure As would have 10 electrons and 8 electrons for each oxygen. So, in the total distribution of the electrons in the structure, we will have the 32 electrons that we calculate in the first step (figure 1).
Finally, in the oxidation number calculation, we have to start with the oxidation number of oxygen. <u>The oxidation number of O is -2</u> then when we <u>multiply by the number of atoms</u> we will get -8, so the As must have an oxidation number of +5 in order to obtain a total charge of -3 (figure 2).
Explanation:Naturally occurring zinc (30Zn) is composed of the 5 stable isotopes 64Zn, 66Zn, 67Zn, 68Zn, and 70Zn with 64Zn being the most abundant (48.6% natural abundance). Twenty-five radioisotopes have been characterised with the most abundant and stable being 65Zn with a half-life of 244.26 days, and 72Zn with a half-life of 46.5 hours. All of the remaining radioactive isotopes have half-lives that are less than 14 hours and the majority of these have half-lives that are less than 1 second. This element also has 10 meta states.
Zinc has been proposed as a "salting" material for nuclear weapons. A jacket of isotopically enriched 64Zn, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope 65Zn with a half-life of 244 days and produce approximately 1.115 MeV[2] of gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several years. Such a weapon is not known to have ever been built, tested, or used.[3]
List of isotopes
Methanol will float on glycerine.
Answer:
Option D. ⁴⁰₁₉K⁺¹
Explanation:
The following data were obtained from the question:
Proton number = 19
Neutron number = 21
Electron number = 18
Complete symbol of isotope =.?
Next, we shall determine the atomic number of the isotope. This is illustrated below:
Atomic number of an element is simply the number of protons in the atom of the element. Thus,
Atomic number = proton number
Proton number = 19
Therefore,
Atomic number = proton number = 19
Since the atomic number of the isotope is 19, the isotope is simply potassium with symbol K.
Next, we shall determine the mass number of the isotope. This can be obtained as follow:
Proton number = 19
Neutron number = 21
Mass number =.?
Mass number = Proton + Neutron
Mass number = 19 + 21
Mass number = 40
Next, we shall determine the charge on the isotope. This can be obtained as follow:
Proton number = 19
Electron number = 18
Charge =.?
Charge = Proton – Electron
Charge = 19 – 18
Charge = +1
Summary:
Atomic number = 19
Mass number = 40
Symbol = K
Charge = +1
Complete symbol = ⁴⁰₁₉K⁺¹