Question

name:
chemical bonds - ionic vs. covalent
directions: using the table below define each of the given bond types. then work to identify the types of bonds in the given compounds.

bond type	definition
covalent (polar and non - polar)
metallic
compound	element #1 (m or nm)	element #2 (m or nm)	bond type
nacl	m	nm	ionic
h₂o
ch₄
caf₂
nh₃
ccl₄
kbr
br₂
alloy of cu and zn (brass)

Explanation:

Step1: Recall bond - type rules

Ionic bonds form between a metal (M) and a non - metal (NM). Covalent bonds form between non - metals. Metallic bonds are in metals or metal alloys.

Step2: Analyze $H_2O$

Hydrogen ($H$) is a non - metal and oxygen ($O$) is a non - metal. So, the bond in $H_2O$ is covalent. Since oxygen is more electronegative than hydrogen, it is a polar covalent bond. Element #1 (H) is NM, Element #2 (O) is NM, Bond Type is Covalent (Polar).

Step3: Analyze $CH_4$

Carbon ($C$) and hydrogen ($H$) are non - metals. The bond in $CH_4$ is covalent. The electronegativity difference is small, so it is a non - polar covalent bond. Element #1 (C) is NM, Element #2 (H) is NM, Bond Type is Covalent (Non - Polar).

Step4: Analyze $CaF_2$

Calcium ($Ca$) is a metal and fluorine ($F$) is a non - metal. So, the bond in $CaF_2$ is ionic. Element #1 (Ca) is M, Element #2 (F) is NM, Bond Type is Ionic.

Step5: Analyze $NH_3$

Nitrogen ($N$) and hydrogen ($H$) are non - metals. Nitrogen is more electronegative than hydrogen, so the bond in $NH_3$ is a polar covalent bond. Element #1 (N) is NM, Element #2 (H) is NM, Bond Type is Covalent (Polar).

Step6: Analyze $CCl_4$

Carbon ($C$) and chlorine ($Cl$) are non - metals. The electronegativity difference leads to polar bonds, but due to the symmetrical structure, $CCl_4$ has non - polar covalent bonds overall. Element #1 (C) is NM, Element #2 (Cl) is NM, Bond Type is Covalent (Non - Polar).

Step7: Analyze $KBr$

Potassium ($K$) is a metal and bromine ($Br$) is a non - metal. So, the bond in $KBr$ is ionic. Element #1 (K) is M, Element #2 (Br) is NM, Bond Type is Ionic.

Step8: Analyze $Br_2$

Bromine ($Br$) is a non - metal. Two bromine atoms form a non - polar covalent bond. Element #1 (Br) is NM, Element #2 (Br) is NM, Bond Type is Covalent (Non - Polar).

Step9: Analyze Brass (Alloy of Cu and Zn)

Copper ($Cu$) and zinc ($Zn$) are metals. The bond in brass is metallic. Element #1 (Cu) is M, Element #2 (Zn) is M, Bond Type is Metallic.

Answer:

Compound	Element #1 (M or NM)	Element #2 (M or NM)	Bond Type
$CH_4$	NM	NM	Covalent (Non - Polar)
$CaF_2$	M	NM	Ionic
$NH_3$	NM	NM	Covalent (Polar)
$CCl_4$	NM	NM	Covalent (Non - Polar)
$KBr$	M	NM	Ionic
$Br_2$	NM	NM	Covalent (Non - Polar)
Alloy of Cu and Zn (Brass)	M	M	Metallic