Chemistry Clinical Sciences 1-3 Flashcards

Chemistry Revision from Lectures 1-3

1
Q

What is matter?

A

Matter is anything that has mass.

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2
Q

What is a physical change?

A

Physical changes are the same material it just changes state.

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3
Q

In a physical change, if the material does not change, what does?

A

Energy needed to break/ make bonds.

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4
Q

What are properties of matter?

A

Density- Mass to volume ratio.
Melting point- Temperature solid to liquid.
Boiling point- Temperature liquid to gas.
Refractive Index- How light passing through a material is bent.
Malubility- The ability an object has to be shaped by hammering.
Ductility- The ability an object has to be shaped by pulling into a wire.
Electrical Conductivity- Ability to transmit electricity.
Heat conductivity- Ability to transfer heat.

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5
Q

What are intensive properties?

Give 3 examples of intensive properties.

A

Intensive Properties DO NOT depend on the amount of matter present. They are used to identify substances.
Density, colour and boiling point.

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6
Q

What are extensive properties?

Give 3 examples of extensive properties.

A

Extensive properties depend on the amount of matter present.
Mass, volume and weight.

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7
Q

What are physical properties a result of?

To examine the physical properties of a substance what must the substance be?

A

Molecular formula and intermolecular forces.

The substance must be PURE.

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8
Q

What are chemical properties a result of?

A

Electrons in the outer shell around the nucleus.

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9
Q

What are Colloids?

A

Mixtures which look homogeneous but are actually heterogeneous.

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10
Q

What is a phase?

A

A distinctive form of matter. Eg. gas, liquid or solid.

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11
Q

What is fixed about a pure substance?

How are pure substances separated or change identity?

A

Fixed set of physical properties.

Cannot be separated by physical processes and can only change identity by CHEMICAL METHODS.

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12
Q

How do you know when a substance is pure?

Examples of pure substances.

A

All molecules have the SAME MOLECULAR FORMULA in the substance.
Elements and Compounds

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13
Q

What is a mixture?

A

TWO or MORE SUBSTANCES which are NOT CHEMICALLY BONDED together.

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14
Q

How are Mixtures separated?

A

Physical Processes.

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15
Q

What is a homogenous mixture?

A

SINGLE PHASE mixture with the SAME PROPERTIES throughout the mixture with UNIFROM CHARACTERISTICS.

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16
Q

What is a heterogenous mixture?

A

Has MUTIPLE PHASES with VARIABLE PROPERTIES with a NON- UNIFORM APPEARANCE.

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17
Q

What is an element?

A

Is the simplest form of matter that has a unique set of properties. It cannot be split into two or more simple substances by chemical means.

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18
Q

What is a compound?

A

Is a substance that contains two or more elements chemically combined into a fixed proportion.

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19
Q

What is a molecule?

A

2 or more atoms bonded together. Atoms in defined proportions.

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20
Q

What did Dalton describe in his Atomic Theroy?

A

All Matter is composed of atoms.
Different elements have different atoms which are characterised by atomic weight. All atoms of same element are identical.
Compounds are two or more atoms in fixed ratios. For example water formula is H2O and Dalton thought the formula for water was OH.
Chemical reactions rearrange atoms which changes the ratios so changes the compound.

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21
Q

Properties of Atoms

A
  1. NUCLEUS contains almost all of the atom’s MASS.

2. Combining power is the atom’s ability to form chemical bonds (VALENCY).

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22
Q

What is Valency and what does this depend on?

A

VALENCY is the NUMBER OF BONDS an element can make, which all depends on how many ELECTRONS are in the element’s HIGHEST ENERGY LEVEL.

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23
Q

What are electrons?

What is the nucleus?

A

ELECTRONS are negatively charged and determine atoms physical and chemical properties.

Nucleus is positively charged and contains the atoms neutrons and PROTONS- which is also known as the MASS NUMBER.

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24
Q

What is the Relative Atom Mass Definition?

A

Mass of one atom of an element divided by the mass of 1/12 of an atom of carbon- 12.
(Average mass of each of an element’s isotopes).

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25
Q

What is relative molecular mass?

A

RMM/Mr is the mass of 1 molecule.

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26
Q

What is a solution?

A

HOMOGENOUS MIXTURE formed when one substance DISSOLVES in another.

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27
Q

What is a Solute?

What is Solvent?

A

The substance that dissolves.

The substance that does the dissolving.

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28
Q

How do you separate a mixture?

A

In a mixture use the differences in physical properties.

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29
Q

Name and describe the physical processes which separate mixtures.

A

FILTRATION- Particle size (Liquid/ Solid).
CRYSTALISATION- Solubility (Solid in Solution).
EXTRACTION- Solubility (Solid/ Liquid in Solution).
DISTILLATION- Components selected by boiling point (Liquid to liquid).
MAGNETISATION- Magnetic metals from other compounds.
CHROMATOGRAPHY- Components selected by affinity (attraction) to stationary phase.

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30
Q

What is an atom made up of?

A

Protons, neutrons and electrons.

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31
Q

What are nucleons?

A

Protons and Neutrons.

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32
Q

What is the mass number/ atomic mass?

A

Protons and Neutrons

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33
Q

What is the atomic number?

A

Number of protons.

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34
Q

What is an orbital?

A

Regions of space with electrons occupy.

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35
Q

What is a shell?

A

Orbitals are grouped into families which are called shells.

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36
Q

Give an example of an orbital, a sub shell and a shell.

A

Orbital- 2px
Sub shell- 2p
Shell- 2s+ 2p

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37
Q

What is an isotope?

A

An ISOTOPE has a different number of neutrons in each atom of the same element so different isotopes are different forms of the same element.

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38
Q

What is the relative atomic mass of an element?

A

The mass of each isotope added together divided by how many isotopes there are for that element= Average mass.

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39
Q

When do stable isotopes change?

A

Stable isotopes only change when we change it.

40
Q

When does an unstable/ radioactive isotope change?

What does the change result in?

A

The unstable isotope undergoes spontaneous disintegration (breaking down) of the nucleus to become a stable nucleus. The spontaneous disintegration results in the emission of small particles/ radiation.

41
Q

What is the use of hydrogen-2?

A

Vitimin Research

42
Q

What is the use of Carbon- 13?

A

Molecular fingerprinting, for example dope testing.

43
Q

What isotopes (Stable or Unstable) does Mass Spectrometry work with?

A

Both unstable/ stable isotopes

44
Q

How does Mass Spectrometry measure?

A

It measures the molecular weight of atoms. Compounds by observing the MASS (M) TO CHARGE (Z) RATIO.

45
Q

How does Mass Spectrometry work?

A

Mass Spectrometry is done by an atom/ molecule being converted into an ion by knocking an electron out of it. Ions can be separated on the basis of mass and motions in magnetic/ electrical field (charge).

46
Q

What can mass spectrometry determine?

A

ISOTOPIC ABUNDANCES Identify SMALL MOLECULES/ PROTEINS.

47
Q

What does the position of the peaks on a mass spectrometry graph show?
What does the relative abundance show on a mass spectrometry graph?

A

Mass of Nucleus/ Atomic Mass.

How much there is of that isotope in that sample.

48
Q

Why does an unstable radioisotope nucleus undergo radioactive decay?

A

To seek energetic stability.

49
Q

What is the definition of a half life of a radioactive substance?

A

The time taken for the activity of a given amount of a radioactive substance to decay to half of its initial value.

50
Q

MECHANISM OF RADIOACTIVE DECAY- ALPHA:
What particle is given out from the nucleus?
What charge is this particle and how does it effect the original nucleus?

A

Emission of an alpha particle (helium atom).
Alpha particle is positively charged (+2).
Mass reduces by 4 and charge reduces by 2.

51
Q

MECHANISM OF RADIOACTIVE DECAY- GAMMA:
What is the change in mass and charge of the original nucleus?
What is given out from the nucleus? Why?
What can also leave the nucleus in an excited state?

A

No change to mass or charge in decay equation.
Emission of electromagnetic radiation because the radioactive isotope is in a high energy state so when radiation is emitted it loses this state?
Alpha and Beta.

52
Q

MECHANISM OF RADIOACTIVE DECAY- BETA MINUS:
What is given out from the nucleus? Why?
What is the change to mass and charge?

A

Emission of an electron.
Nucleus has excess neutrons so transforms into proton (+1) and electron (-1) as charge is balanced.
Electron does not belong in nucleus so kicked out.
Mass= No change
Charge= +1

53
Q

MECHANISM OF RADIOACTIVE DECAY- BETA PLUS:
What is given out from the nucleus? Why?
What is the change to mass and charge?

A

Emission of a POSITRON (anti-electron).
Too many protons in nucleus so protons change into neutron and positron (+1 charge). Overall charge stays the same.
Mass= No Change
Charge= -1

54
Q

Why does the nucleus’s charge change?

A

Nucleus is only shown so protons given it overall charge.

55
Q

What is the capture Process?

A

When a small particle (neutron/ electron) collide with a nucleus and are added to it.

56
Q

What is Neutron Capture?

A

Neutron added to the nucleus.

57
Q

Describe the Boron Capture Theory?

What can Boron Capture Theory be used todo?

A

A neutron is added to Boron. After the neutron is added Boron’s MASS NUMBER INCREASES and so becomes UNSTABLE. Since the radioactive isotope is unstable it undergoes RADIOACTIVE DECAY producing an ALPHA particle.
Used on localised tissue to TARGET TUMOURS.

58
Q

What is the penetrating power of Alpha, Beta and Gamma?

A

ALPHA is stopped by PAPER.
BETA is stopped by ALUMINIUM.
GAMMA is stopped by CONCRETE/ LEAD

59
Q

Applications of unstable isotopes- Sterilisation of Medical Supplies:

A

E.g., 60 Co- Gamma does not damage material whereas Beta does.

60
Q

Applications of unstable isotopes- Smoke Detectors

A

241 Am is a radioactive isotope and travels across a chamber which records charge. If smoke is in the chamber it obstructs the charge reading so no charge can be registered. ALPHA.

61
Q

Applications of unstable isotopes- Imaging

A

Short life isotopes can be used for imaging as you do not want them in the body very long. Imaging agent in the blood. Tumour needs a blood supply. Less blood in the centre of the tumour because of mutation in cells, so scan shows the poorer blood supply through not a lot of imaging agent.

62
Q

Applications of unstable isotopes- Positron Emission Tomography (PET)

A

18 F- Fluro- deoxy glucose (FGD) has a half-life of 110 minutes. Positron Beta and radiation goes a small distance in the body which meets the electron and produces radiation which is detectable outside the body. Look at cell metabolism (measure) how much sugar uptake- tumours a lot.

63
Q

Therapeutic applications of unstable isotopes:

A

Need iodine for thyroid gland. Have normal iodine not radioactive blocks radioactive iodine. 132 I = Diagnostic and 131 I = Destroying thyroid because of cancer or since it is overactive (produces too many hormones.)

64
Q

What is atomic mass?

A

Mass of a single atom (Electrons, protons and neutrons).

65
Q

What is the mass number?

A

The number of protons and neutrons in the nucleus.

66
Q

What is the atomic number?

What does the number identify?

A

Number of protons in the nucleus.

The atomic number identifies the number and the charge of the nucleus.

67
Q

What was the Dobereiner’s Law of Triads?

A

1817- Looked at elements with similar chemical and physical properties and these together. Arranged them in order of atomic masses. The middle element was the average of the other 2 atomic weights.

68
Q

Who inverted the Law of the Octaves?
What did the Law of the Octaves state?
What were the problems associated with the law of the Octaves?

A

1864- British Chemist- Newlands.
If you arranged elements in sets of 8 according to atomic mass then chemical and physical properties would repeated but only with lighter elements.

Arranged too strictly.
Heavier elements did not fit- No idea about electron shell structure and now this effected chemical properties.

69
Q

What did Mendeleev do in 1869?

What was the problems associated with this periodic table?

A

Prepared to take elements out of the order of mass if reactivity showed they fitted somewhere better.
Predictions on undiscovered elements and what their properties would be.

His periodic table could not deal with isotopes.

70
Q

Who created the Modern Periodic table in 1940?

How did he construct the modern periodic table?

A

Glen Seaborg

Arranged elements on atomic number not on atomic mass.

71
Q

In the periodic table how are elements arranged?

In the periodic table what is repeated?

A

In increasing order of atomic number from left to right.

The chemical and physical properties of elements are repeated.

72
Q

What does the periodic law state?

A

Properties of elements are periodic functions of their atomic structure.

73
Q

In families of elements what do these elements have in common?

A

Similar observable behaviour and atomic structure.

74
Q
Alkali metals:
Group?
Colour?
Strong/ Soft Metals. Why?
Reactive? So?
A

Group 1
Silver Coloured
Soft Metals (Weak bonds)
Highly reactive and so are rarely found in element form in nature.

75
Q
Halogens:
Group?
States are room temperature?
Reactivity? So?
Melting/ boiling point?
A

Group 7
At room temperature F (Gas), Cl (Gas), Br (Liquid) and I (Solid).
Highly reactive and toxic so react that it makes a bond with itself. Eg. Cl2.
Gases or low boiling/ melting point materials.

76
Q

Alkaline Earth Metals:
Group?
Colour?
Reactivity?

A

Group 2
Silver Coloured
Similar reactivity to alkali metals.

77
Q

Nobel Gases:
Group?
Reactivity?
Condition?

A

Group 8/ 0
Chemically Inert
Non-metallic and gaseous at standard condition.

78
Q

Metalloids:
How many elements?
Properties?

A

6 elements.
Properties of metals and non-metals. Conduct electricity well like a metal and has the ability to form covalent bonds like a non-metal.

79
Q

Non Metals:

Properties?

A

Not able to conduct electricity or heat well.
Brittle and cannot be rolled into a wire or pounded into sheets (opposite to metals).
No metallic properties and cannot reflect light.

80
Q
Lanthanides:
How many elements?
Atomic Numbers?
Known as? 
What block do they fill in the periodic table?
Colour?
What happens when exposed to air?
Melting/ Boiling Point?
A
15 Elements= Atomic Numbers 57-71
Can be known as rare earth metals.
Partially filled f- block.
Shiny + shivery white. 
Stain easily when exposed to air.
High melting and boiling points.
81
Q
Actinides:
How many elements?
Atomic Numbers?
Structure?
Can form what?
What do they combine with? Why?
A

ACTINIDES:
15 elements= Atomic Number 89- 103
Dense metals with particular structures.
Can form many ALLOTROPE.
Unstable and naturally occurring so combine directly with non- metals.

82
Q

What is an allotrope?

A

Particular arrangement of atoms/ ions with properties characteristic of an element.

83
Q

Transition Metals:
What block do they fill in the periodic table?
Properties?
What do they form?
Why do they readily undergo oxidation and reduction?
How do they combine with other elements?

A

Transition metals is an element with at least one oxidation state and has a partially filled d- subshell. High density, melting and boiling point.
Formed coloured compounds and complex ions which are surrounded by 6 ligands.
Multiple valencies and ions which readily undergo oxidation and reduction.
Use electrons from outer two energy levels to combine with other elements.

84
Q

General Characteristics of groups in the periodic table- NUMBER OF ELECTRON SHELLS.

A

Equal to the number of the period to which the element belongs to.
Down group number of electrons shells increases by one.

85
Q

General Characteristics of groups in the periodic table- PROPERTIES OF ELEMENTS.

A

All elements within a group have similar chemical and physical properties.

86
Q

General Characteristics of groups in the periodic table- REACTIVITY

A

Metals become more reactive as you move down a group.

Non- metals become less reactive as you descend down the group.

87
Q

General Characteristics of groups in the periodic table- METALLIC CHARACTER

A

Increases as you move down group. Apparent in groups where non- metals are at the top and then metals at the bottom.

88
Q

General Characteristics of groups in the periodic table- SIZE IN ATOMS

A

Larger as you descend down group because more filled energy shells.
Smaller across a period because stronger nuclear charge so stronger attraction between electrons and nucleus.

89
Q

General Characteristics of groups in the periodic table- VALENCY

A

The number of chemical bonds formed by an atom.
Valency of a monatomic ion= Charge.
Some elements have multiple valencies and so have multiple oxidation states. like transition metals.
Heavier elements tend to have multiple valencies (Pb 2/4).
P+ N also have 3 or 5 valency.

90
Q

General Characteristics of groups in the periodic table- NUMBER OF VALENT ELECTRONS

A

Number of electrons in outer shell of an atom remains unchanged when moving down the group.

Group 1, 2, 3 , 4 = Valency= Group Number
Group 4, 5, 6, 7, 8= Valency= 8- Group.

91
Q

How do you work out Empirical Formula? (Walk through steps)

A
  1. Mass Percentage
  2. Divide by atomic mass to find out how many atoms there are in the mass.
  3. Divide by smallest one so can get a ratio to compare the number of atoms within the mass.
  4. Answer
92
Q

How do you calculate molecular formula?

A

Calculate the mass of the Empirical formula.
Divide the RMM of the compound by the empirical formula.
Work out Molecular Formula.

93
Q

What is the Molecular Formula?

A

How many atoms are there in the actual molecule.

94
Q

What is the Empirical Formula?

A

Simplest ratio of atoms in a molecule.

95
Q

Describe how you would work out Percentage composition by a formula.

A
  1. Mass of whole compound (Denominator).
  2. Elements mass (Numerator).
  3. Fraction and the x 100 to get it as a percentage.