Unit 3 questions

Considering electron affinity alone, state the most probable way (losing, gaining, sharing) in which the following atoms could attain a valence octet. Also state the number of electrons involved A. K B. Ca C. Ga D. Ge E. As F. Se G. Br H. Kr I. C

A. Loses one B. Loses two C. Loses three D. Gains, loses, or shares four E. Gains or shares three F. Gains or shares two G. Gains or shares one H. Already has a valence octet I. Gains, loses, or shares four (Pp149-150)

Identify the types of atoms (metal or nonmetal) in the following compounds and then tell whether the compounds are predominately ionic, covalent, or metallic A. Sodium chloride (NaCl) B. Red brass (Sn-Cu-Zn alloy) C. Magnesium bromide (MgBr2) D. Carbon dioxide (CO2) E. Stainless steel (Fe-Ni-Cr alloy)

A. Metal and nonmetal;ionic bond B. Metals; metallic bond C. Metal and nonmetal; ionic bond D. Nonmetals; covalent bond E. Metals; metallic bond (pp150,152-153,158-161,163)

Why do atoms form chemical bonds?

Atoms form bonds because they want a lower energy and more stable electron configuration (p149)

Why are the diatomic elements not found in nature as single atoms?

Diatomic elements have very high electron affinities. Being single atoms, they quickly form bonds with other elements around them. They are relatively stable only when in the diatomic state.

True or false, there is no purely covalent bond

False. Purely covalent bonds form between atoms having the same electronegativity (eg diatomic elements) p152

Why does hydrogen act like a group 17 element when forming covalent bonds?

Hydrogen needs only one electron to complete its valence electron shell and is a diatomic element, similar to group 17 (pp153-154)

Why does the octet rule not always refer to a stable arrangement of eight valence electrons?

The first four or five elements usually bond to attain the electron configuration of helium, which has only two valence electrons, and transitions often share more than their eight valence electrons (p149)

Which one of the three bond types is distinctly different from the other two? Explain why this is so

The metallic bond is distinctly different from covalent and ionic bonds. Metallic bonding involves atoms sharing electrons among many atoms. Covalent and ionic bonds depend on the electronegativity differences between atoms and the sharing of electrons to a greater or lesser extent between just a few atoms. (pp150-153, 158-161)

True or false, Many bonded atoms attain a stable electron configuration without having a valence octet

True (p149)

True or false, there is no purely ionic bond

True (p152)

True or false, it is not possible to identify a metallic bond between two or a few metal atoms. A metallic bond exists only in the presence of a great many metal atoms

True (p161)

True or false, a valence energy band containing innumerable energy levels accounts for the mirror like luster associated with metals

True (pp163-164)