Chapter 2 - Chemistry Review

Question 1

charge magnitude

Answer 1

1.602e-19 C (positive for protons, negative for electrons)

Question 2

atomic number

Answer 2

“Z” number of protons in the nucleus. For an electrically neutral or complete atom also equals the number of electrons.

Question 3

atomic mass

Answer 3

“A” the sum of the masses of protons and neutrons within the nucleus.

Question 4

isotope

Answer 4

the 2+ atomic masses of an atom

Question 5

atomic weight

Answer 5

the weighted average of the atomic masses of the atom’s naturally occurring isotopes

Question 6

atomic mass unit

Answer 6

“amu” may be used to compute atomic weight. 1 amu = 1/12 of the atomic mass of carbon 12

Question 7

mole (Avogadro’s number)

Answer 7

6.022e23 atoms or molecules

Question 8

1amu/atom =

Answer 8

1 g/mol

Question 9

quantum mechanics

Answer 9

A set of principles and laws that govern systems of atomic and subatomic entities.

Question 10

Bohr atomic model

Answer 10

Early attempt where electrons are assumed to revolve around the nucleus in circles and they make quantized energy levels.

Question 11

wave-mechanical model

Answer 11

electron is considered to exhibit both wave-like and particle-like characteristics, characterized by quantum numbers

Question 12

quantum numbers

Answer 12

size, shape, spacial orientation, principal quantum number

Question 13

principal quantum number

Answer 13

K, L, M, N : related to the distance of an electron from the nucleus

Question 14

second quantum number “l”

Answer 14

s, p, d, f : signifies the subshell, related to the shape of the electron subshell

Question 15

third quantum number “m(l)”

Answer 15

1, 3, 5, 7 : number of energy states for each subshell

Question 16

fourth quantum number “m(s)”

Answer 16

+1/2, -1/2 : the spin moment

Question 17

electron states

Answer 17

values of energy that are permitted for electrons

Question 18

Pauli exclusion principle

Answer 18

Stipulates that each electron state can hold no more than two electrons (having opposite spins)

Question 19

ground state

Answer 19

when all the electrons occupy the lowest possible energies

Question 20

electron configuration

Answer 20

the manner in which electron states are occupied

Question 21

valence electrons

Answer 21

the electrons which occupy the outermost shell

Question 22

stable electron configurations

Answer 22

when the states in the outermost or valence electron shell are completely filled (inert or noble gases)

Question 23

periods

Answer 23

horizontal rows

Question 24

group

Answer 24

columns, have similar valence electron structures as well as chemical and physical properties

Question 25

inert gases

Answer 25

Group 0

Question 26

halogens

Answer 26

Group VIIA

Question 27

alkali and alkaline earth metals

Answer 27

Groups IA, IIA

Question 28

transition metals

Answer 28

Groups IIIB - IIB

Question 29

electropositive elements

Answer 29

elements under the metal classification, capable of giving up their few valence electrons to become positively charged ions

Question 30

electronegative elements

Answer 30

right-hand side of the table, readily accept electrons to form negatively charged ions

Question 31

electronegativity trend

Answer 31

increases in moving from left to right and from bottom to top

Question 32

Force-potential energy relationship for two atoms

Answer 32

``` E = ∫ F*dr E(N) = ∫∞r F(A)*dr + ∫∞r F(R)*dr E(N) = E(A) + E(R) ```

Question 33

bonding energy

Answer 33

E(0) the energy at the minimum point of the net energy curve

Question 34

types of primary or chemical bonds (3)

Answer 34

ionic, covalent, metallic

Question 35

ionic bonding

Answer 35

primary bond, always found in compounds of metallic and nonmetallic elements, steal electrons, non-directional, often ceramics, hard and brittle, insulative

Question 36

coulombic force

Answer 36

positive and negative ions attract one another, ionic bonding

Question 37

attractive energy - interatomic separation relationship

Answer 37

E(A) = -A/r

Question 38

repulsive energy - interatomic separation relationship

Answer 38

E(R) = B/r^n

Question 39

non-directional

Answer 39

magnitude of the bond is equal in all directions

Question 40

covalent bonding

Answer 40

primary bond, often nonmetallic elemental molecules or elemental solids, share electrons, often polymeric materials

Question 41

metallic bonding

Answer 41

primary bond, electrons "float", good conductors

Question 42

ion cores

Answer 42

metallic bonds, the non valence electrons and atomic nuclei

Question 43

secondary bonds, Van der Waals bonds

Answer 43

weak in comparison to primary or chemical bonds, arise from dipoles (positive end of one dipole and negative region of adjacent attract)

Question 44

hydrogen bonding

Answer 44

secondary bond, when hydrogen is covalent bonded to F, O or N so the other side is a essentially a positively charged bare proton

Question 45

polar molecule

Answer 45

when permanent dipole moment exist by virtue of asymmetry