Question

Material Science

Question 1

Muscle fibers slide smoothly across each other in both directions.

True

False

Question 2

Cell membranes are composed of single layers of fat molecules.

True

False

Question 3

In mammals, the percentage composition of fats and minerals is roughly the same.

True

False

Question 4

Both RNA and DNA have a double helix structure.

True

False

Question 5

The primary constituents of muscles are

	a)	the proteins kerotin and actin
	b)	the proteins lycine and actin
	c)	the proteins actin and liposine
	d)	the proteins glycine and lycine
	e)	the proteins myocin and actin

Question 6

Hydroxyapatite is a component of endoskeletons.

True

False

Question 7

There are thousands of types of amino acids.

True

False

Question 8

Amorphous silicon is a component of some biomaterials.

True

False

Question 9

The biosynthesis of both collagen and polysaccharides starts in the cell nucleus.

True

False

Question 10

After going through alkyline hydrolysis, the remaining solids are primarily hydroxyapatite.

True

False

Question 11

Calcium carbonate is a mineral found in some biomaterials.

True

False

Question 12

Proteins, chitin, and cellulose are build up from proteins

True

False

Question 13

There are thousands of types of proteins.

True

False

Question 14

Chitin is the most abundant natural polymer.

True

False

Question 15

Keratin is formed from a structure of living cells.

True

False

Question 16

Some biopolymers are hard.

True

False

Question 17

Polymeric biomaterials are comprised of collagen and elastin.

True

False

Question 18

Cell membranes are made of double layers of proteins.

True

False

Question 19

Which is NOT an example of a hard biopolymer?

		a)Eggs
		b)Insect Shells
		c)Hooves
		d)Nails
		e)Cellulose

Question 20

Polysaccharides are built up hierarchically from amino acids.

True

False

Question 21

Unit cells have faces that are

	a)	rhombus
	b)	square
	c)	rectangular
	d)	parallelegrams
	e)	circular

Question 22

Unit cells are

		a)the building blocks of crystalline material
		b)the building blocks of DNA
		c)the building blocks of polymers
		d)the building blocks of amorphous materials
		e)the building blocks of biomaterials

Question 23

Which radioactive semi-metal is the only element with a Simple-Cubic (SC) structure?

		a)Polonium
		b)Uranium
		c)Radium
		d)Plutonium
		e)Dilthium

Question 24

The common crystal structures in metal are

		a)FCC, BCC, HCP
		b)FCC, BCC, HCP, and SC
		c)HCC, BCC, FCP
		d)HCC, BCC, FCP and SC
		e)FCC, SEC, BCC

Question 25

Diffraction results in

		a)constructive interference
		b)delamination of the planes
		c)reverse polarization
		d)altered planar spacing
		e)destructive interference

Question 26

Unit cell indexing schemes provide

		a)location information for grain boundaries
		b)descriptions of the atoms, planes, and axis directions
		c)diffraction indexes for the crystal material
		d)the location of the unit cell in the larger crystalline matrix
		e)the packing arrangement

Question 27

Hexagonal crystal structures cannot be close-packed.

True

False

Question 28

To determine crystal structure and spacing, scientists use

		a)magnetic resonance imaging
		b)X-ray diffraction
		c)optical microscopes
		d)scanning electron microscopes
		e)atomic force microscopes

Question 29

A scanning probe (aka atomic force) microscope can be used to image and manipulate individual atoms.

True

False

Question 30

Crystal planar density is taken as

		a)the number of atoms per unit area for a plane
		b)the planar stacking order
		c)the number of atoms that are closely packed
		d)the number of equivalent atoms per unit cell
		e)the number of atoms per unit length for an axis

Question 31

The atomic packing factor represents

		a)the mass ratio of the unit cell
		b)the number of nearest-neighbor atoms
		c)the fraction of solid sphere volume in the unit cell
		d)the unit cell edge length (a) divided by the atomic radius (R)
		e)the density of the material

Question 32

When an elemental solid can have more than one crystal structure, it is said to have

		a)allotropy
		b)polymorphism
		c)polytropy
		d)elemorphism
		e)anthropomorphis

Question 33

The crystallographic linear density

		a)is determined by the atomic packing factor
		b)is six for HCP unit cells
		c)is five for BCP unit cells
		d)is determined by the coordination number
		e)is how many atoms lie along a unit length in that direction

Question 34

Bragg's law specifies

		a)the condition for when electrons will be refracted upon striking a crystal
		b)the condition for when light will be polarized upon striking a crystal
		c)the condition for when x-rays will be absorbed upon striking a crystal
		d)the condition for when x-rays will be refracted upon striking a crystal
		e)the condition for when light will be refracted upon striking a crystal

Question 35

Two features of a crystal unit cell structure are

		a)atomic number and elemental packing factor
		b)the number of interstitial and host atoms
		c)coordination number and atomic packing factor
		d)the number of faces and the number of atoms
		e)the number of substitutional and interstitial atoms

Question 36

Imperfections in semiconductors are used to create transistors and other electronic devices.

True

False

Question 37

The majority of crystalline solids are single crystals

True

False

Question 38

The grain structure of a polycrystalline material can be observed in the material without significant preparation.

True

False

Question 39

There are three types of electron microscopes, Transmission (TEM), Scanning (SEM), and Tunneling (TUEM).

True

False

Question 40

Defects are important for solid catalysts

True

False

Question 41

The mean intercept length is a measure of grain diameter.

True

False

Question 42

Imperfections in materials do not generally change their properties.

True

False

Question 43

The mean intercept length is computed from the average length of a grain boundary edge.

True

False

Question 44

Catalysts chemically combine with the reactant molecules in order to speed up the reaction.

True

False

Question 45

For a particular material, the higher the temperature the greater the number of vacancies.

True

False

Question 46

A twin boundary is a linear defect where the screw angles on each side of the boundary are equal.

True

False

Question 47

The regular pattern of crystal order is disrupted at a grain boundary.

True

False

Question 48

Solid solutions can only be formed by liquid material cooling to a solid.

True

False

Question 49

Alloys do not usually have significantly difference properties of the constituent metals.

True

False

Question 50

When an atom is missing from a crystal structure position, it is referred to as a self-interstitial.

True

False