Chem Exam 2

Front 1

isotope

Back 1

atoms with the same atomic number but different number of neutrons

Front 2

weighted average = isotope's abundance + mass

Back 2

weighted average (amu)

Front 3

decay

Back 3

when an unstableisotope undergoes a process to become stable

Front 4

inert

Back 4

elements in nature that do not combine with other elements to form comounds

Front 5

electrical charge

Back 5

fundamental property of both protons and electrons that causes them to exert forces on one another

Front 6

repel eachother

Back 6

Particles with like charges ______

Front 7

attract eachother

Back 7

Particles with opposite charges ______

Front 8

amu

Back 8

unit of mass defined as 1/12 of a carbon-12 nucleus

Front 9

ion

Back 9

charge particles that loses or gains one or more of its electrons

Front 10

cation

Back 10

posititively charged ions, metal (lose electrons)

Front 11

anions

Back 11

negatively charged ions, non-metal (gain electrons)

Front 12

nucleon

Back 12

nucleus densely packed with protons and neutrons, held together by a strong nuclear force

Front 13

If they contain even numbers of protons and neutrons, least stable when they contain an odd number of both

Back 13

Nuclei are most stable when:

Front 14

band of stability

Back 14

the higher the atomic number, the less stable the atom becomes (as nuclides get heavier, the proton/neutron ratio increases to 1.5)

Front 15

1. Alpha

2. Beta

3. Gamma

Back 15

Types of Radiation

Front 16

1. there is an imbalance in the nucleus due to the ratio of protons and neutrons

2. neutrons attract each other all the time

3. protons only attract one another at short distances

4. the unstable nucleus will become radioactive and fly apart increasing the number of neutron needed to stabilize it

Back 16

Why are atomic nuclei unstable?

Front 17

Antoine-Henri Becquerel

Back 17

continued Roentgen's study, created the x-ray

Front 18

radioactivity

Back 18

result of nuclear instability, nuclei that are too heavy are unstable and decay to attain stability therefore releasing parts of their nucleus, these emitted particles are radiation

Front 19

alpha radiation

Back 19

1. alpha particle consists of 2 protons, 2 neutrons, and a 2+ charge (same thing as a He atom)

2. when alpha particles collide with matter, they generate a large number of ions and therefore can damage biological molecules

3. because of their large size, alpha particles have low penetrating power (do a lot of damage, but don’t go very far)

4. atom loses 2 protons

Front 20

beta radiation

Back 20

1. beta particle is an energetic electron emitted by an atomic nucleus because electrons are smaller than a helium nucleus

2. beta particles penetrate more easily

3. less ionizing power, therefore do less damage to biological molecules

4. atom adds a proton

Front 21

gamma radiation

Back 21

1. different than alpha and beta because they are electromagnetic

2. highest penetrating power, requiring several inches of lead to stop them

Front 22

half life

Back 22

the time required for half the nuclei in a sample to decay

Front 23

1. alpha decay - lose 2 protons

2. beta minus decay - add 1 proton

3. beta plus decay - lose 1 proton

4. positron emission - lose 1 proton

5. electron capture - lose 1 proton

Back 23

Processes isotopes go through to become more stable - Nuclear Transmissions:

Front 24

induced fission (transmutation)

Back 24

a process where unstable nuclei of an element are bombarded with other nuclei or particles to produce a new element

Front 25

William Roentgen

Back 25

credited with the discovery of X-radiation

Front 26

Marie Curie

Back 26

discovered two new elements, came up with the term radioactivity

Front 27

spontaneous fission

Back 27

parent splits into daughters

Front 28

Manhattan Project

Back 28

largest scientific endeavor of its time, the race to beat Germany to the atomic bomb; Oppenheimer was the scientific director; results: dropped 2 bombs ending WWII and killing over 200,000 in Japan

Front 29

Fermi

Back 29

discovered the fission of Uranium

Front 30

Hahn & Meitner

Back 30

discovered that bombarding neutrons actually split the U nucleus, and when it split tremendous amounts of energy were also released

Front 31

mass defect

Back 31

refers to the difference in mass of an atom and the sum of the masses of protons, neutrons, and electrons in the atom (predicted mass - actual mass); shows how much mass was converted to energy

Front 32

nuclear binding energy

Back 32

energy released from an atom when the nucleus is formed, measure of the stability of an atomic nucleus

Front 33

curie/becquerel

Back 33

units of radioactivity

Front 34

1. Somatic (cell) damage

2. Genetic (hereditary) damage

Back 34

Radiation's Effect on Biological Systems

Front 35

when radiation enters the body, water molecules absorb the energy (human body 65% water); the O-H bond breaks and forms a very reactive chemical species known as free radicals

Back 35

Genetic Damage from Radiation

Front 36

rad

Back 36

radiation absorption dose, measuring unit for amount of radiationabsorbed by 1 gram of matter

Front 37

rem

Back 37

radiation equivalent in humans, unit for measuring biological effects ofdifferent kinds of radiation on humans

Front 38

fission

Back 38

splitting of an atom in two, and large amounts of energy emitted, heavy elements split into lighter ones

Front 39

fusion

Back 39

lighter elements are fused into heavier ones

Front 40

Pros:

1. Cheaper

2. Produces a large amount of energy from a small amount of fuel

Cons:

1. An explosion/malfunction can send radioactive material into the atmosphere

2. Not renewable

3. Disposing of radioactive waste

Back 40

Pros and Cons of Nuclear Fission

Front 41

Pros:

1. No radioactive waste

2. Available in unlimited amounts

3. The He produced is not radioactive

Cons:

1. Challenging to produce on Earth

2. Expensive

3. No known material that can sustain such high temperatures

Back 41

Pros and Cons of Nuclear Fusion

Front 42

1. Radiation used to diagnose diseases

2. Treat diseases

3. Determining age of organic material

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How Radioactive Isotopes and Used in Industry and Medicine

Front 43

relative atomic mass unit

Back 43

average mass of atoms of an element from a single given sample or source

Front 44

Jon Jakob Berzelius

Back 44

used experimentally determined relative masses and compiled the first arrangement of the known elements

Front 45

John Newland

Back 45

developed a better way to organize the 60 known elements, noticing that when elements were organized by increasing mass that similarities in elemental properties occurred every 8th element (Law of Octaves)

Front 46

Demitri Mendeleev

Back 46

arranged elements according to increasing atomic mass, repeating patterns of chemical properties, predicted the presence of unknown elements

Front 47

Lothar Meyer

Back 47

arranged elements according to increasing atomic mass, repeating patterns of physical properties

Front 48

Henry J Moseley

Back 48

corrected any inconsistencies in the periodic table

Front 49

group of elements

Back 49

vertical columns in the periodic table that group elements of similar properties together

(1-18 or 1A-8A)

Front 50

noble gases

Back 50

column 8A, have 8 valence electrons, all are stable and have full outer orbits and are chemically inert (do not react with other elements to form compounds)

Front 51

alkali metals

Back 51

column 1A, have 1 valence electron, very reactive, lose the electron in a chemical reaction to acquire a noble gas configuration

Front 52

alkali earth metals

Back 52

column 2A, have two valence electrons and lose them in a chemical reaction to acquire a noble gas configuration

Front 53

chalcogens

Back 53

column 6A, often gain two electrons when react to attain a stable noble gas electron configuration

Front 54

halogens

Back 54

group 7A, undergo vigorous chemical reactions to attain an additional electron

Front 55

metals

Back 55

tend towards the left side of the periodic table, lose electrons in their chemical reactions, good conductors of heat and electricity, shiny, solid at room temp.

Front 56

non-metals

Back 56

tend toward the right side of the table, gain electrons in their chemical reactions, poor conductors of heat and electricity, dull, many are gases at room temp

Front 57

metalloids

Back 57

found between the metals and non-metals, show mixed tendencies, shiny solids with low conductivity

Front 58

transitional metals

Back 58

groups 3B-2B in the center of the table, lose electrons in their chemical reactions but do not necessarily acquire noble gas configurations

Front 59

In the 19th century, some scientists recognized that some elements had very similar chemical properties.

Back 59

What led to the organization of elements in a periodic table?

Front 60

Bohr model

Back 60

one dimensional model that shows atoms in uniform rings where

n = 1, holds a max of 2 electrons

n = 2, holds a max of 8 electrons

n = 3, holds a max of 8 electrons

made up of orbits

Front 61

quantum mechanical model

Back 61

three dimentional model that shows where atoms will most likely be, made of up of orbitals

Front 62

valence electrons

Back 62

electrons in in the outer orbit of an atom, critical in determining the element’s properties (how they will combine with other elements)

Front 63

two

Back 63

Each orbital has a max of _____ subshells.

Front 64

molar mass

Back 64

Avogadro’s number, number value of the atomic mass of an element in gram per mole

Front 65

mole

Back 65

counting unit, means 6.02x10^23 of a given substance

Front 66

mole concept

Back 66

relates the mass of a sample of an element to the number of atoms in it so that we we can determine the number of atoms by weighing it

Front 67

compound

Back 67

the combination of atoms or ions of the elements, properties are totally different that those of the individual element it is made up of, can be molecular or ionic, can be organic or inorganic

Front 68

molecular compounds

Back 68

made up of two or more molecules, molecules held together by forcesweaker than chemical bonds

Front 69

ionic compounds

Back 69

made up of two or more ions (cation or anion), ions chemically bonded together

Front 70

organic compounds

Back 70

contains C, H, O, or N

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inorganic compounds

Back 71

contains any elements other than C, H, O, or N

Front 72

molecular formulas

Back 72

shows elements and numbers of atoms in formula but no arrangment

Front 73

structural formulas

Back 73

shows elemental arrangement of atoms in 2D or 3D

Front 74

ionic formulas

Back 74

shows neutral combinations of ions

Front 75

oxidization

Back 75

gain electrons

Front 76

reduction

Back 76

loose electrons