MTL 200 EXAM REVISION
QUESTIONS AND 100% CORRECT
ANSWERS!!
1.What is an isotope?
2. What is the wave-mechanical model?
3. What are the four quantum numbers and what do they represent?
4. What is Pauli's Exclusion Principle?
*1. Varying number of neutrons, giving atoms different masses
*2. Electrons that exhibit both wave and particle-like characteristcs; probability distribution
*3.
(1) Principle quantum number (n): energy levels
(2) Angular momentum (l): orbitals; 0 to (n-
1) l = 0: s orbital ~ spherical shape
l = 1: p orbital ~ lobes that extend on x,y,z axes (3 per level)
l = 2: d orbital ~ bunched shape ( 5 per level)
l = 3: f orbital ~ bigger bunch (7 per level)
(3) Magnetic quantum number (Ml)
How many orbitals of a type per level: (-l) to (+l)
(4) Spin quantum number (Ms)
+1/2 or -1/2 - via 'Pauli's exclusion principle'
*4. No two elements can have the same quantum state; must be of opposite spin
1. What is the Aufbau principle?
2. What is paramagnetic and diamagnetic?
3. What is an orbital?
4. What is ground state?
5.What is electropositivity and electronegativity?
,1. Quantum's shells can't be exactly the same in 2 electrons of the same atom, shells can only
hold 2 electrons
2. Paramagnetic: unpaired electrons (using configurations) and are attracted by a magnetic
field Diamagnetic: is all electrons are paired
3. A region of probability where an orbital case be found
4. Electron configurations are the nucleus of an atom with lower energy levels
5. Positivity: capable of giving their valence electrons to become positively
charges Negativity: ready to accept electrons to form negatively charges ions
1. What is ionic bonding and what is its direction?
2. What are Coulombic forces?
3. What is covalent bonding and what is its direction?
4. What is hybridizations?
5. What is metallic bonding?
6. What are secondary bonds?
*1. Metallic plus non-metallic atoms and is NON-DIRECTIONAL
2. Forces of attraction or repulsion between 2 likes and unlike charges
*3. A small difference in electronegativity and DIRECTIONAL; very strong bonds with a
high boiling point
4. Mixing of 2 or more atomic orbitals, which result in more orbital overlap
5. Bonds found in metals and its alloys, Directional
,*6. Van Der Waal forces which are present due to molecular and atomic
dipoles Van Der Waal forces are also the weakest type of bond
Chapter 3:
1. What is a crystalline material? and what can form one
2. What is a Crystal structure?
3. What is the atomic hard-sphere model and what does it represent?
4. What is a lattice structure?
*1. A material in which the atoms are situated in a repeating or periodic way over LARGE
atomic distances
• all metals, many ceramics and certain polymers form crystalline structures
*2. Manner in which atoms, ions or molecules are spatially arranged
*3. Solid spheres with well defined diameters representing nearest-neighbour touch
, 4. 3D array of points coinciding with atom positions
1. What is a unit cell?
2. What is important metallic crystal structures?
3. In FCC, where the atoms located and what is the edge length (a)?
4. What is a coordination number? FCC? BCC? HCP?
5. What is atomic packing factor?
6. What is the number of atoms: FCC, BCC, HCP
*1. Smallest subgroups of atoms that form a repetitive pattern
2. No restrictions for number and position of nearest neighbour atoms, creates dense
atomic packings, each sphere forms ion cores
*3. Atoms in each of the corners and on each face, a = 2root(2)
*4. The number of nearest neighbour or touching atoms. FCC = 12, BCC = 8, HCP = 12
*5. Sum of sphere volumes of all atoms in unit cell, FCC = 0.74
*6. FCC = 4, BCC = 2, HCP = 6
1. In BCC, where are the atoms located, and what is its edge length?
2. In simple cubic, where are the atoms and why?
3. In HCP, where are the atoms? APF?
4. What is polymorphism?
*1. All 8 corners and a single atom in the centre, a = 4R/root(3)
2. Atoms only in the corners of the cells, no metallic elements have SC bc of low APF
3. Top and bottom faces have 6 atoms, surround and single hexagon in the centre, an extra plane
going from top to bottom has 3 more atoms, APF = 0.74 (same as FCC bc of close packed)
QUESTIONS AND 100% CORRECT
ANSWERS!!
1.What is an isotope?
2. What is the wave-mechanical model?
3. What are the four quantum numbers and what do they represent?
4. What is Pauli's Exclusion Principle?
*1. Varying number of neutrons, giving atoms different masses
*2. Electrons that exhibit both wave and particle-like characteristcs; probability distribution
*3.
(1) Principle quantum number (n): energy levels
(2) Angular momentum (l): orbitals; 0 to (n-
1) l = 0: s orbital ~ spherical shape
l = 1: p orbital ~ lobes that extend on x,y,z axes (3 per level)
l = 2: d orbital ~ bunched shape ( 5 per level)
l = 3: f orbital ~ bigger bunch (7 per level)
(3) Magnetic quantum number (Ml)
How many orbitals of a type per level: (-l) to (+l)
(4) Spin quantum number (Ms)
+1/2 or -1/2 - via 'Pauli's exclusion principle'
*4. No two elements can have the same quantum state; must be of opposite spin
1. What is the Aufbau principle?
2. What is paramagnetic and diamagnetic?
3. What is an orbital?
4. What is ground state?
5.What is electropositivity and electronegativity?
,1. Quantum's shells can't be exactly the same in 2 electrons of the same atom, shells can only
hold 2 electrons
2. Paramagnetic: unpaired electrons (using configurations) and are attracted by a magnetic
field Diamagnetic: is all electrons are paired
3. A region of probability where an orbital case be found
4. Electron configurations are the nucleus of an atom with lower energy levels
5. Positivity: capable of giving their valence electrons to become positively
charges Negativity: ready to accept electrons to form negatively charges ions
1. What is ionic bonding and what is its direction?
2. What are Coulombic forces?
3. What is covalent bonding and what is its direction?
4. What is hybridizations?
5. What is metallic bonding?
6. What are secondary bonds?
*1. Metallic plus non-metallic atoms and is NON-DIRECTIONAL
2. Forces of attraction or repulsion between 2 likes and unlike charges
*3. A small difference in electronegativity and DIRECTIONAL; very strong bonds with a
high boiling point
4. Mixing of 2 or more atomic orbitals, which result in more orbital overlap
5. Bonds found in metals and its alloys, Directional
,*6. Van Der Waal forces which are present due to molecular and atomic
dipoles Van Der Waal forces are also the weakest type of bond
Chapter 3:
1. What is a crystalline material? and what can form one
2. What is a Crystal structure?
3. What is the atomic hard-sphere model and what does it represent?
4. What is a lattice structure?
*1. A material in which the atoms are situated in a repeating or periodic way over LARGE
atomic distances
• all metals, many ceramics and certain polymers form crystalline structures
*2. Manner in which atoms, ions or molecules are spatially arranged
*3. Solid spheres with well defined diameters representing nearest-neighbour touch
, 4. 3D array of points coinciding with atom positions
1. What is a unit cell?
2. What is important metallic crystal structures?
3. In FCC, where the atoms located and what is the edge length (a)?
4. What is a coordination number? FCC? BCC? HCP?
5. What is atomic packing factor?
6. What is the number of atoms: FCC, BCC, HCP
*1. Smallest subgroups of atoms that form a repetitive pattern
2. No restrictions for number and position of nearest neighbour atoms, creates dense
atomic packings, each sphere forms ion cores
*3. Atoms in each of the corners and on each face, a = 2root(2)
*4. The number of nearest neighbour or touching atoms. FCC = 12, BCC = 8, HCP = 12
*5. Sum of sphere volumes of all atoms in unit cell, FCC = 0.74
*6. FCC = 4, BCC = 2, HCP = 6
1. In BCC, where are the atoms located, and what is its edge length?
2. In simple cubic, where are the atoms and why?
3. In HCP, where are the atoms? APF?
4. What is polymorphism?
*1. All 8 corners and a single atom in the centre, a = 4R/root(3)
2. Atoms only in the corners of the cells, no metallic elements have SC bc of low APF
3. Top and bottom faces have 6 atoms, surround and single hexagon in the centre, an extra plane
going from top to bottom has 3 more atoms, APF = 0.74 (same as FCC bc of close packed)
