Question

homework:
show the electron transfer for the following compounds. write the chemical form

1. lithium and nitrogen
2. potassium and oxygen
3. calcium and fluorine
4. strontium and iodine

use criss-cross method to write the formula for each of the following.

1. potassium nitride
2. calcium iodide
3. strontium phosphide
4. aluminum selenide

name these compounds:

1. $\text{mg}_3\text{n}_2$
2. $\text{srf}_2$
3. $\text{li}_3\text{p}$
4. $\text{cs}_3\text{n}$
5. $\text{rb}_2\text{o}$
6. $\text{bai}_2$
7. $\text{aln}$
8. $\text{mgo}$
9. $\text{znbr}_2$
10. $\text{al}_2\text{o}_3$
11. $\text{cao}$
12. $\text{li}_2\text{o}$

write the formulas for these compounds:

1. calcium iodide
2. sodium carbide
3. strontium phosphide
4. lithium phosphide

Explanation:

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Part 1: Electron Transfer & Chemical Formulas

Step1: Identify ion charges

Lithium ($\text{Li}^+$), Nitrogen ($\text{N}^{3-}$); Potassium ($\text{K}^+$), Oxygen ($\text{O}^{2-}$); Calcium ($\text{Ca}^{2+}$), Fluorine ($\text{F}^-$); Strontium ($\text{Sr}^{2+}$), Iodine ($\text{I}^-$)

Step2: Balance charges via criss-cross

1. $\text{Li}^+$ and $\text{N}^{3-}$: $3\text{Li}^+ + \text{N}^{3-}

ightarrow \text{Li}_3\text{N}$

1. $\text{K}^+$ and $\text{O}^{2-}$: $2\text{K}^+ + \text{O}^{2-}

ightarrow \text{K}_2\text{O}$

1. $\text{Ca}^{2+}$ and $\text{F}^-$: $\text{Ca}^{2+} + 2\text{F}^-

ightarrow \text{CaF}_2$

1. $\text{Sr}^{2+}$ and $\text{I}^-$: $\text{Sr}^{2+} + 2\text{I}^-

ightarrow \text{SrI}_2$

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Part 2: Criss-Cross Method Formulas

Step1: List ion charges

1. $\text{K}^+$, $\text{N}^{3-}$; 6. $\text{Ca}^{2+}$, $\text{I}^-$; 7. $\text{Sr}^{2+}$, $\text{P}^{3-}$; 8. $\text{Al}^{3+}$, $\text{Se}^{2-}$

Step2: Cross charges for subscripts

1. $\text{K}_3\text{N}$
2. $\text{CaI}_2$
3. $\text{Sr}_3\text{P}_2$
4. $\text{Al}_2\text{Se}_3$

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Part 3: Name Ionic Compounds

Step1: Cation (metal) first, anion (nonmetal) with -ide

1. $\text{Mg}_3\text{N}_2$: Magnesium nitride
2. $\text{SrF}_2$: Strontium fluoride
3. $\text{Li}_3\text{P}$: Lithium phosphide
4. $\text{Cs}_3\text{N}$: Cesium nitride
5. $\text{Rb}_2\text{O}$: Rubidium oxide
6. $\text{BaI}_2$: Barium iodide
7. $\text{AlN}$: Aluminum nitride
8. $\text{MgO}$: Magnesium oxide
9. $\text{ZnBr}_2$: Zinc bromide
10. $\text{Al}_2\text{O}_3$: Aluminum oxide
11. $\text{CaO}$: Calcium oxide
12. $\text{Li}_2\text{O}$: Lithium oxide

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Part 4: Write Compound Formulas

Step1: Identify ion charges, criss-cross

1. $\text{Ca}^{2+}$, $\text{I}^-$: $\text{CaI}_2$
2. $\text{Na}^+$, $\text{C}^{4-}$: $\text{Na}_4\text{C}$
3. $\text{Sr}^{2+}$, $\text{P}^{3-}$: $\text{Sr}_3\text{P}_2$
4. $\text{Li}^+$, $\text{P}^{3-}$: $\text{Li}_3\text{P}$

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Answer:

1. Electron transfer: $3\text{Li}

ightarrow 3\text{Li}^+ + 3e^-$; $\text{N} + 3e^-
ightarrow \text{N}^{3-}$; Formula: $\text{Li}_3\text{N}$

1. Electron transfer: $2\text{K}

ightarrow 2\text{K}^+ + 2e^-$; $\text{O} + 2e^-
ightarrow \text{O}^{2-}$; Formula: $\text{K}_2\text{O}$

1. Electron transfer: $\text{Ca}

ightarrow \text{Ca}^{2+} + 2e^-$; $2\text{F} + 2e^-
ightarrow 2\text{F}^-$; Formula: $\text{CaF}_2$

1. Electron transfer: $\text{Sr}

ightarrow \text{Sr}^{2+} + 2e^-$; $2\text{I} + 2e^-
ightarrow 2\text{I}^-$; Formula: $\text{SrI}_2$

1. $\text{K}_3\text{N}$
2. $\text{CaI}_2$
3. $\text{Sr}_3\text{P}_2$
4. $\text{Al}_2\text{Se}_3$
5. Magnesium nitride
6. Strontium fluoride
7. Lithium phosphide
8. Cesium nitride
9. Rubidium oxide
10. Barium iodide
11. Aluminum nitride
12. Magnesium oxide
13. Zinc bromide
14. Aluminum oxide
15. Calcium oxide
16. Lithium oxide
17. $\text{CaI}_2$
18. $\text{Na}_4\text{C}$
19. $\text{Sr}_3\text{P}_2$
20. $\text{Li}_3\text{P}$