Answer: 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here iron is having an oxidation state of +3 called as 
cation and oxide 
is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral 
.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Part 1: Potassium, and Rubidium.
Part 2: Calcium has 20 protons and 20 electrons because the atomic number for calcium is 20 and that determines how many protons there are and in an atom, the number of protons is the same number of electrons. Calcium has about 20 neutrons. I got the number of Neutrons by subtracting the mass number(40.078) and the atomic number(20), I got 20.078. Round to the nearest whole number because you cannot have half or partial neutron. So, Calcium has 20 protons, 20 electrons, and 20 neutrons,
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Answer:
a reference book about weather
Explanation:
The number of moles of sodium dichromate from the number of moles of oxygen atoms can be determined through stoichiometry. Using the molecular formula of the compound, Na2Cr2O7, 1 mole of the compound contains 7 moles of oxygen. Hence, 14 moles O2*(1 mole Na2Cr2O7/ 7 mole O2) is equal to 2 moles <span>Na2Cr2O7.</span>
The remaining moles of C is 5.01 moles while the remaining moles of F₂ is 0.
<h3>
Reaction between Carbon and Fluorine </h3>
The reaction between carbon and Fluorine is given as;
C + 2F₂ -------> CF₄
1 : 2 1
from the reaction above,
2 moles of F₂ requires 1 mole of C
7.88 mole of F₂ will require: 7.88/2 = 3.94 moles of C and 3.94 moles of CF₄.
The remaining moles of C = 8.95 - 3.94 = 5.01 moles while the remaining moles of F₂ is 0.
Learn more about moles here: brainly.com/question/15356425
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