The table in the first image shows the ions that each element can form. To write the formula of an ionic compound using the table, we first need to identify the charges of the ions. Then, we need to combine the ions in such a way that their charges balance out. For example, to write the formula of the ionic compound formed between the aluminum ion (Al^3+) and the sulfate ion (SO4^2-), we would combine one aluminum ion with three sulfate ions. Therefore, the formula of the ionic compound is Al2(SO4)3. The criss-cross method is a simple way to write the formulas of ionic compounds. To use the criss-cross method, we first need to identify the charges of the ions. Then, we criss-cross the charges to write the formula of the compound. For example, the formula of the compound formed between the calcium ion and the chloride ion is CaCl2, because the calcium ion has a charge of 2+ and the chloride ion has a charge of 1-.
To form an ionic compound, a metal cation and a nonmetal anion must combine in such a way that their charges balance out. For example, the sodium ion (Na+) has a charge of 1+, while the chloride ion (Cl-) has a charge of 1-. Therefore, one sodium ion and one chloride ion will combine to form the ionic compound sodium chloride (NaCl).
The table in the image shows the ions that each element can form. For example, fluorine can form the fluoride ion (F-), bromine can form the bromide ion (Br-), and sulfur can form the sulfate ion (SO4^2-).
To write the formula of an ionic compound using the table, we first need to identify the charges of the ions. Then, we need to combine the ions in such a way that their charges balance out. For example, to write the formula of the ionic compound formed between the aluminum ion (Al^3+) and the sulfate ion (SO4^2-), we would combine one aluminum ion with three sulfate ions. This is because the aluminum ion has a charge of 3+ and the sulfate ion has a charge of 2-. Therefore, the formula of the ionic compound is Al2(SO4)3.
Here is a table of the formulas of the ionic compounds that can be formed from the ions listed in the image:
Ion Fluoride (F-) Bromide (Br-) Sulfate (SO4^2-) Nitrate(NO3^-)
(NH4+) NH4F NH4Br (NH4)2SO4 NH4NO3
(Al^3+) AlF3 AlBr3 Al2(SO4)3 Al(NO3)3
(Pb^2+) PbF2 PbBr2 PbSO4 Pb(NO3)2
(Fe^2+) FeF2 FeBr2 FeSO4 Fe(NO3)2
The second image shows a table of ions and the formulas of the compounds they produce. The ions in the table are Ca, LU, NH4, Al, Pb, and FE(0). The anions are Cl, OH, SO4, and NO3.
To write the formula of a compound using the criss-cross method, we first need to identify the charges of the ions. The calcium ion (Ca2+) has a charge of 2+, while the chloride ion (Cl-) has a charge of 1-. The lutetium ion (Lu3+) has a charge of 3+, while the hydroxide ion (OH-) has a charge of 1-. The ammonium ion (NH4+) has a charge of 1+, while the sulfate ion (SO42-) has a charge of 2-. The aluminum ion (Al3+) has a charge of 3+, while the nitrate ion (NO3-) has a charge of 1-. The lead ion (Pb2+) has a charge of 2+, while the iron(0) atom (Fe(0)) has a charge of 0.
Once we know the charges of the ions, we can write the formula of the compound by criss-crossing the charges. For example, the formula of the compound formed between the calcium ion and the chloride ion is CaCl2, because the calcium ion has a charge of 2+ and the chloride ion has a charge of 1-. The formula of the compound formed between the lutetium ion and the hydroxide ion is Lu(OH)3, because the lutetium ion has a charge of 3+ and the hydroxide ion has a charge of 1-. The formula of the compound formed between the ammonium ion and the sulfate ion is (NH4)2SO4, because the ammonium ion has a charge of 1+ and the sulfate ion has a charge of 2-. The formula of the compound formed between the aluminum ion and the nitrate ion is Al(NO3)3, because the aluminum ion has a charge of 3+ and the nitrate ion has a charge of 1-. The formula of the compound formed between the lead ion and the iron(0) atom is PbFe, because the lead ion has a charge of 2+ and the iron(0) atom has a charge of 0.
Here is a table of the formulas of the compounds produced from the listed ions:
Ion Cl OH SO4 NO3
Ca2+ CaCl2 Ca(OH)2 CaSO4 Ca(NO3)2
Lu3+ LuCl3 Lu(OH)3 Lu2(SO4)3 Lu(NO3)3
NH4+ NH4Cl NH4OH (NH4)2SO4 NH4NO3
Al3+ AlCl3 Al(OH)3 Al2(SO4)3 Al(NO3)3
Pb2+ PbCl2 Pb(OH)2 PbSO4 Pb(NO3)2
Fe(0) PbFe Fe(OH)2 FeSO4 Fe(NO3)2