An isoelectronic series is where all of the ions listed have the same number of electrons in their atoms. When an atom has net charge of zero or neutral, it has equal number of protons and electrons. Hence, it means that the atomic number = no. of protons = no. of electrons. If these atoms become ions, they gain a net charge of + or -. Positive ions are cations. This means that they readily GIVE UP electrons, whereas negative ions (anions) readily ACCEPT electrons. So, to know which of these are isoelectronic, let's establish first the number of electron in a neutral atom from the periodic table:
Na=11; K=19; Rb=37; Cs = 55; Ca=20; S=16; Mg=12; Li=3; Be=4; B=5; C=6, Ar = 18
A. Na⁺: 11-1 = 10 electrons
K⁺: 19 - 1 = 18 electrons
Rb⁺: 37-1 = 36 electrons
B. K⁺: 19 - 1 = 18 electrons
Ca²⁺: 20 - 2 = 18 electrons
Ar: 18 electrons
S²⁻: 16 +2 = 18 electrons
C. Na⁺: 11-1 = 10 electrons
Mg²⁺: 12 - 2 = 10 electrons
S²⁻: 16 +2 = 18 electrons
D. Li=3 electrons
Be=4 electrons
B=5 electrons
C=6 electrons
The answer is letter B.
15mL because if it started as 20 mL and went to 35mL when u put in pyrite, the pyrite takes up 15mL
There are 6 atoms of oxygen on the reactant side of the following equation: 2Fe2O3 + 3C → 4Fe + 3CO2. Details about atoms can be found below.
<h3>How to find number of atoms?</h3>
The number of atoms of an element in a balanced equation is the amount of that element involved in the reaction.
According to this question, Iron oxide reacts with carbon to produce iron and carbon dioxide as follows:
2Fe2O3 + 3C → 4Fe + 3CO2
In this reaction, 2 × 3 atoms = 6 atoms of oxygen are present on the reactant side of the equation.
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Answer:
NO3-
Explanation:
Given the reaction equation;
Au(s) + 3NO3-(aq) + 6H+(aq)→Au3+(aq) + 3NO2(g) + 3H2O (l).
We can consider the oxidation states of species on the left and right hand sides of the reaction equation;
Au is in zero oxidation state on the left hand side and an oxidation state of +3 on the righthand side.
NO3- is in oxidation state of +5 on the righthand side and NO2 is in + 4 oxidation state.
H+ is in + 1 oxidation state on both the left and right hand sides of the reaction equation.
Since reduction has to do with a decrease in oxidation number, it follows that NO3- was reduced in the reaction.