CHEM 160 Midterm 4

radioactive decay definition

when radioactive nuclei spontaneously decompose into smaller nuclei

radioactivity definition

release of high-energy particles and/or high-energy electromagnetic radiation from the nucleus of an atom

parent nuclide

the nucleus that is undergoing radioactive decay

daughter nuclide

the new nucleus that is formed

mass number equation

mass number=protons plus neutrons

isotopic symbol

mass number above, atomic number below (the periodic table one)

alpha particles

⁴₂He

beta particles

⁰_-1e

gamma rays

⁰₀gamma

some unstable nuclei can emit positrons

⁰₊₁e

some unstable nuclei will undergo electron capture

⁰_-1e on the LEFT side

alpha decay

is the most ionizing but least penetrating of the types of radioactivity

beta decay

• half the ionizing ability, 10 times more penetrating than alpha

• in the nucleus, a neutron transmutes into a proton

gamma emission

• no change in composition of the nucleus

• least ionizing, most penetration

• gamma rays are high energy photons

with electron capture, is there particle emission?

no, but a captured electron combines with a proton in the nucleus to form a neutron.

the shorter the half life…

the more nuclei decay every second, therefore the HOTTER the sample is, the more radioactive it is

is the rate of radioactive change affected by temperature?

no the rate of radioactive change is not affected by temperature

what does the measured ratio of carbon-14/carbon-12 after death determine?

the measured ratio of carbon-14/carbon-12 after death can determine how long ago the organism died.

what is the strong force?

the particles in the nucleus are held together by a very strong attractive forced found called the strong force

what is mass defect?

the loss in mass that occurs when protons and neutrons combine to form a nucleus.

the loss in mass is converted into energy that is released during the nuclear reaction and is thus a direct measure of the _______?

the loss in mass is converted into energy that is released during the nuclear reaction and is thus a direct measure of the binding energy holding the nucleus together.

It is the combination of _____ that must be conserved?

It is the combination of mass and energy that must be conserved

fission

the large nucleus splits into two smaller nuclei

fusion

small nuclei can be accelerated to smash together to make a larger nucleus

how much energy does fission and fusion release?

both fission and fusion release enormous amounts of energy

does fusion or fission release more energy?

fusion releases more energy per gram than fission does

what is a chain reaction?

a chain reaction occurs when a reactant in the process is also a product of the process

what is the critical mass?

the minimum amount of fissionable isotope needed to sustain the chain reaction

what do nuclear reactors use to generate electricity?

nuclear reactors use fission to generate electricity

what kind of energy does radiation have?

radiation has high energy, enough energy to knock electrons from molecules and break bonds

why does the 4s orbital fill before the 3d?

because the 4s is lower in energy than the 3d

electron configuration order

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴

how are complex ions made?

when a cation combines with multiple anions or neutral molecules it makes a complex ion

what are ligands

the attached anions or neutral molecules are called ligands

what is the coordination number

the number of ligand donor atoms that surround a central metal ion in a complex

what is a coordinate covalent bond

a bond that forms when the pair of electrons is donated by one atom

what is a chelate?

a chelate is a complex ion containing a multidentate ligand, this ligand is called the chelating agent

bromide, Br^-

ligand name: bromo

carbonate, CO₃^2-

ligand name: carbonato

chloride, Cl^-

ligand name: chloro

cyanide, CN^-

ligand name: cyano

fluoride, F^-

ligand name: fluoro

glycinate, gly^-

ligand name: glycinato

hydroxide, OH^-

ligand name: hydroxo

oxalate, C₂O₄^-

ligand name: oxalato

thiocyanate, SCN^-

ligand name: thiocyanato if ligand donor atom is S

ligand name: isothiocyanato if ligand donor atom is N

ammonia, NH₃

ligand name: ammine

water, H₂O

ligand name: aqua

carbon monoxide, CO

ligand name: carbonyl

ethylenediamine, en

ligand name: ethylenediamine

aluminum

anion name: aluminate

chromium

anion name: chromate

cobalt

anion name: cobaltate

copper

anion name: cuprate

gold

anion name: aurate

iron

anion name: ferrate

manganese

anion name: manganate

nickel

anion name: nickelate

platinum

anion name: platinate

zinc

anion name: zincate

silver, Ag

anion name: argentate

lead, Pb

anion name: plumbate

tin, Sn

anion name: stannate

what are isomers

compounds with same formula but different arrangement of atoms

what are constitutional isomers

compounds with different connections between atoms

what are stereoisomers

compounds with same connections but different spatial arrangement of atoms

what are linkage isomers

isomers with different metal-ligand bonds

what are ionization isomers

isomers that yield different ions in solution

what are diastereoisomers

non-mirror-image isomers

what are enantiomers

mirror-image isomers (like our hands)

what are geometric isomers

stereoisomers that differ in spatial orientation of ligands

cis isomer

ligands are next to each other on the same side of the molecule

trans isomer

the ligands are on opposite sides of the molecule

what does achiral mean?

objects that do not have a handedness to them

what does chiral mean?

objects that have a handedness to them. nonidentical mirror images like a HAND

what does crystal field theory?

a model that views the bonding in complexes as arising from electrostatic interactions and considers the effect of the ligand charges on the energies of the metal ion d orbitals

what crystal field splitting energy change like in tetrahedral complexes?

crystal field splitting energy change is small in tetrahedral complexes

what crystal field splitting energy change like in square planar complexes?

crystal field splitting energy change is much larger in square planar complexes

what is electron configuration for Cr

irregular, 4s¹3d⁵

what is electron configuration for Cu

irregular, 4s¹3d¹⁰

what is electron configuration for Mo

irregular, 5s¹4d⁵

what is electron configuration for Ru

irregular, 5s¹4d⁷

what is electron configuration for Pd

irregular, 5s⁰4d¹⁰

where can we find the valence electrons?

the shell that is the largest coefficient.

prefix for 1

mono

prefix for 2

di

prefix for 3

tri

prefix for 4

tetra

prefix for 5

penta

prefix for 6

hexa

prefix for 7

hepta

prefix for 8

octa

prefix for 9

nona

prefix for 10

deca

bis

2 ligands

tris

3 ligands

aluminum oxidation state is always?

3+

Ag electron configuration

irregular; [Kr]5s¹4d¹⁰

NH₃

ammonia

NH₄⁺

ammonium