MATSE Exam Practice Exam Questions with Correct

1 MATSE Exam/ Practice Exam Questions with Correct Verified Answers/ Rated A+

Metallic bonds are different from covalent bonds in that the shared valence electrons are delocalized.True or False? - ANS - True

Aluminum has a face centered cubic (feck) structure with an atomic radius of 0.143 nm and an atomic weight of 26.98 g/mol. (a) Calculate the density of Al from this information. (b) What is the planar density of atoms in the (110) plane.

• (a) 1.35 g/L, (b) 6.11 atoms/nm^2
• (a) 2.71 g/L, (b) 8.64 atoms/nm^2
• (a) 0.678 g/L, (b) 8.64 atoms/nm^2
• (a) 2.71 g/L, (b) 6.11 atoms/nm^2 - ANS - B. (a) 2.71 g/L, (b) 8.64 atoms/nm^2

Ethane (CH3CH3) and Fluor methane (CH3F) have the same number of electrons and are essentially the same size. However, ethane has a boiling point of 184.5C and fluor methane has a boiling point of 194.7C. Which answer best explains this 10-degree difference in boiling point in terms of the van der Waals forces present.

• It has nothing to do with van der Waals
• Both molecules have both dispersion and orientation forces present, but fluor methane is a slightly

larger molecule

• Both molecules have dispersion forces, but fluor methane also has orientation forces present
• Both molecules are non-polar, but fluor methane is a slightly larger molecule - ANS - C. Both

molecules have dispersion forces, but fluor methane also has orientation forces present

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2 Covalent interactions are generally long range (i.e., greater than 10 nm).True or false - ANS – False

The number of vacancies per cm^3 in gold at 900C is?

• 1.93x10^17/cm^3
• 3.64x10^18/cm^3
• 6.51x10^22/cm^3
• 5.90x10^22/cm^3 - ANS - B. 3.64x10^18/cm^3

Hydrogen bonding is predominately found between polar molecules True or False - ANS - True

Describe all types of bonding that you would expect to exist in each of the following compounds: a silicon carbide crystal

• Predominantly covalent and some ionic
• Predominantly ionic and some covalent
• Equally ionic and covalent
• Ionic only - ANS - A. Predominantly covalent and some ionic

The first five peaks of the x-ray diffraction pattern for tungsten, which has a BCC crystal structure; an x- ray source with a wavelength of 0.1542 nm was used.11. What are the indices (hill) for the first three peaks?

A. (110), (111), (200)

B. (111), (200), (220)

C. (100), (110), (111)

D. (110), (200), (211) - ANS - D. (110), (200), (211)

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3 Describe all types of bonding that you would expect to exist in each of the following compounds: potassium fluoride (KF)

• Predominantly covalent and some ionic
• Predominantly ionic and some covalent
• Equally ionic and covalent
• Ionic only - ANS - B. Predominantly ionic and some covalent

Describe all types of bonding that you would expect to exist in each of the following compounds: an alloy composed of 90%Al, 7%Si, 3%Mg

• ionic, covalent and metallic
• metallic only
• metallic and ionic
• metallic and van der wails - ANS - D. metallic and van der wails

Describe all types of bonding that you would expect to exist in each of the following compounds: zirconia (ZrO2)

• predominantly ionic and some covalent
• Predominantly covalent and some ionic
• ionic only
• covalent only - ANS - A. predominantly ionic and some covalent

Describe all types of bonding that you would expect to exist in each of the following compounds: ice

• predominantly ionic and some covalent
• van der Waals only
• predominantly covalent, some ionic and van der Waals
• predominantly ionic and some van der Waals - ANS - predominantly covalent, some ionic and van der

Waals

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4 Covalent bonding occurs as a result of columbic attraction and the transfer of valence electrons. True or False? - ANS - False

The density of niobium is 8.58g/cm3. Its atomic mass is 92.91 g/mol and its structure is bcc. (a) Calculate the lattice parameter and the atomic radius from this information. (b) What is the planar density of atoms in the (110) plane.

• (a) a = 0.330 cm; R = 0.143 cm, (b) 26.0 atoms/nm^2
• (a) a = 0.330 nm; R = 0.467 nm, (b) 13.0 atoms/nm^2
• (a) a = 0.330 nm; R = 0.143 nm, (b) 13.0 atoms/nm^2
• (a) a = 0.330 nm; R = 0.117 nm, (b) 26.0 atoms/nm^2 - ANS - C. (a) a = 0.330 nm; R = 0.143 nm, (b)

13.0 atoms/nm^2

Long Range Order (LRO) - ANS - refers to a repeating, or periodic, structure of atoms. When LRO exists, the material has a crystalline structure where the building blocks are unit cells. all metals

the first five peaks of the x-ray diffraction pattern for tungsten, which has a BCC crystal structure; an x- ray source with a wavelength of 0.1542 nm was used.12. Determine the interplanar spacings for the first two peaks

• first peak = 0.228 nm; second peak = 0.159 nm
• first peak = 0.1.59 nm; second peak = 0.228 nm
• first peak = 0.121 nm; second peak = 0.091 nm
• first peak = 0.091 nm; second peak = 0.121 nm - ANS - A. first peak = 0.228 nm; second peak = 0.159

nm

the first five peaks of the x-ray diffraction pattern for tungsten, which has a BCC crystal structure; an x- ray source with a wavelength of 0.1542 nm was used.13. Determine the lattice parameter

• 0.228 nm
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