Atoms, Bonds and Groups - Atoms and Reactions Flashcards Preview

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Flashcards in Atoms, Bonds and Groups - Atoms and Reactions Deck (127):
1

Who was the first person to develop the idea of the atom?

Democritus in the 5th century BC was the first to develop the idea of an atom.

2

From which word is atom derived, and what does it mean?

Atom is derived from the Greek word 'atomos' which means indivisible.

3

Who developed atomic theory?

John Dalton developed atomic theory.

4

In which century was atomic theory developed?

John Dalton developed atomic theory in the 19th century (1800s).

5

What were the key points of atomic theory?

  • atoms are tiny particles that make up elements
  • atoms cannot be divided
  • all atoms of a given element are the same
  • atoms of one element are different from those of every other element

6

Who discovered electrons?

Electrons were discovered by Joseph John (JJ) Thomson by the use of cathode rays.

7

In what year(s) were electrons discovered?

Joseph John (JJ) Thomson discovered electrons by the use of cathode rays 1897-1906.

8

What was used in the discovery of electrons?

Joseph John (JJ) Thomson used cathode rays in his discovery of electrons.

9

What properties of electrons did John Joseph (JJ) Thomson discover?

  • electrons have negative charge
  • can be deflected by both a magnet and an electric field
  • have very small mass

10

What was the original term which John Joseph (JJ) Thomson used for electrons?

John Joseph (JJ) Thomson initially used the term 'corpuscle' to describe electrons.

11

Which atomic model was proposed by John Joseph (JJ) Thomson?

The plum pudding model was proposed by Joseph John (JJ) Thomson.

12

What were the key points of the plum pudding model?

  • negative electrons move around a sea of positive charge
  • atoms have no overall charge

13

Who disproved the plum pudding model?

Ernest Rutherford (actually Hans Geiger and Ernest Marsden) disproved the plum pudding model.

14

In what year was the plum pudding model disproved?

The plum pudding model was dispoved in 1909.

15

How was the plum pudding model disproved?

α particles were directed towards a sheet of very thin gold foil and the deflection was measured. If the plum pudding model was correct then there should be no deflection. Most particles were not deflected at all, however, some were deflected through large angles and some were deflected back to the source. Showed that the positive charge must be concentrated within the atom and not spread.

16

After the discovery of the plum pudding model (1909) what did Ernest Rutherford then propose in 1911?

  • positive charge is concentrated in a nucleus at the centre
  • negative electrons orbit the nucleus just as planets orbit the sun
  • most of the volume of an atom is in the space between the nucleus and the orbiting electrons
  • overall positive and negative charge must balance

17

What did Neils Bohr state in relation to electrons in 1913?

Neils Bohr (1913) stated that electrons must follow certain paths or else they would spin into the nucleus. This was the planetary atom.

18

Who stated that electrons must follow certain paths or they would spin into the nucleus, and thus proposed the planetary atom?

Neils Bohr (1913) stated that electrons must follow certain paths or else they would spin into the nucleus, and thus proposed the planetary atom.

19

In what year was the proton discovered?

The proton was discovered in 1918 by Rutherford.

20

Who discovered the proton in 1918?

Rutherford discovered the proton in 1918.

21

Who suggested that atoms can have the nature of both a wave and a particle?

Louis de Broglie (1923) suggested that atoms can have the nature of both a wave and a particle.

22

In what year did Louis de Broglie suggest that atoms can have the nature of both a wave and a particle?

In 1923, Louis de Broglie suggested that atoms can have the nature of both a wave and a particle.

23

Who suggested that electrons behave like waves in atoms, and also proposed atomic orbitals?

Erwin Schrödinger (1926) suggested that electrons behave like waves in atoms and also proposed the presence of atomic orbitals.

24

In what year did Erwin Schrödinger suggest that electrons behave like waves in atoms and also propose the presence of atomic orbitals?

In 1926, Erwin Schrödinger suggested that electrons behave like waves in atoms and also proposed the presence of atomic orbitals.

25

What did Erwin Schrödinger propose in 1926 which contributed to atomic theory?

In 1926, Erwin Schrödinger proposd that electrons behave like waves in atoms, and also proposed the presence of atomic orbitals.

26

In what year did James Chadwick discover the neutron?

The neutron was discovered in 1932 by James Chadwick by bombarding light elements with high energy α particles.

27

Who discovered the neutron in 1932?

In 1932, James Chadwick discovered the neutron by bombarding light elements with high energy α particles.

28

What method was used in the discovery of the neutron?

In 1932, James Chadwick discovered the neutron by bombarding light elements with high energy α particles.

29

What is it now believed that protons are made of?

It is now believed that protons are made of even smaller particles called quarks.

30

Electrons orbit the nucleus in ....... ?

Electrons orbit the nucleus in shells.

31

TRUE or FALSE

The nucleus is large compared with the overall volume of the atom?

FALSE!

The nucleus is tiny compared with the total volume of the atom.

32

TRUE or FALSE

The nucleus is very dense and makes up most of the mass of the atom?

TRUE!

The nucleus is very dense and makes up most of the mass of the atom.

33

TRUE or FALSE

Most of the atom consists of empty space?

TRUE!

Most of the atom consists of empty space between the tiny nucleus and the electron shells.

34

What is an isotope?

Isotopes are atoms of the same element with different numbers of neutrons.

35

TRUE or FALSE

Atoms tend to have more protons than electrons?

FALSE!

Atoms have the same number of protons and electrons so are electrically neutral.

36

TRUE or FALSE

A proton and a neutron are of virtually the same mass?

TRUE!

A proton and a neutron are of virtually the same mass.

37

What is the atomic number the same as?

The atomic (proton) number is the number of protons in the nucleus of an atom.

38

What is the mass of the atom the same as?

The mass (nucleon) number is the number of particles (protons and neutrons) in the nucleus of an atom.

39

TRUE or FALSE

Carbon exists as a single isotope?

FALSE!

Carbon exists as a mixture of isotopes.

40

TRUE or FALSE

Different isotopes of the same element react differently?

FALSE!

Different isotopes of the same element react in the same way because chemical reactions involve electrons and neutrons make no difference to reactivity.

41

Atoms react by gaining or losing what?

Atoms react by gaining or losing electrons.

42

What is the relative isotopic mass the same as?

The relative isotopic mass is the same as the mass number.

43

What is the problem with the atomic mass?

The problem with the atomic mass is that it neglects the mass of electrons and assumes the mass of protons and neutrons to be 1.0u.

44

What is the unit for counting atoms?

The amount of substance, measured in moles, is the unit for counting atoms.

45

What is the Avogadro constant defined as?

The Avogadro constant, NA, is the number of atoms per mole of the carbon-12 isotope.

46

What symbol is used to represent the Avogadro constant?

NA represents the Avogadro constant.

47

What is the numerical value of the Avogadro constant?

6.02 x 1023 mol -1

48

Define the empirical formula?

The empirical formula is the simplest whole number ratio of atoms of each element present in a compound.

49

n = ?/?

n= m/M

Where m = mass

and M = Mr

50

Define the molar volume

The molar volume is the volume per mole of a gas.

51

What are the units of the molar volume?

The units of molar volume are dm3 mol-1.

52

What is the molar volume at room temperature and pressure?

At room temperature and pressure, the molar volume is approximately 24.0 dm3mol-1.

53

TRUE or FALSE

Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules?

TRUE!

Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.

54

What is the formula to work out the number of moles of gas (if the volume is in dm3)?

To work out the amount in moles of a gas measured in dm3:

n=V/24

Where n is the amount in moles

and V is the volume in dm3

55

What is the formula to calculate the amount in moles of gas if the volume of the gas is measured in cm3?

To calculate the amount in moles of a gas when given the volume measured in cm3:

n=V/24000

Where n is the amount in moles of gas

Where V is the volume of the gas measured in cm3

56

Define the concentration of a solution.

The concentration of a solution is the amount of solute, in mol, dissolved per 1 dm3 (1000cm3) of solution.

57

In a solution with a concentration of 2 mole dm-3, how many moles of solute are dissolved in every 1 dm3 of solution?

In a solution with a concentration of 2 mol dm-3 there are 2 mols of solute dissolved in every 1 dm3 of solution.

58

What is the formula which links the amount of substance in mols, the concentration of a solute and the volume of a solution?

n = c X V

where n is the amount of substance in mols

where c is the concentration of solute in mol dm-3

where V is the volume of solution in dm3

59

What is a standard solution?

A standard solution is a solution is a solution of a known concentration.

60

What concentration is considered 'concentrated'?

'Concentrated' is considered around 10 mol dm -3.

61

What is a species? (in chemistry terms, obv)

A species is any type of particle that takes part in a chemical reaction.

62

What different components may be a 'species'?

  • atom
  • ion
  • molecule
  • empirical formula
  • electron

63

Which elements have giant structures?

  • all metals
  • some non-metals
    • carbon
    • silicon
    • boron

64

What is stoichiometry?

Stoichiometry is the molar relationship between the relative quantities of substance taking part in a reaction.

65

What is the chemical formula for sulphuric acid?

H2SO4

66

What are the four different states of matter?

  • solid
  • liquid
  • gaseous
  • aqueous

67

What state symbol is used to represent something which is aqueous?

The state symbol aq is used to represent something which is in an aqueous state.

68

What is the chemical formula of hydrochloric acid?

HCl is the chemical formula of hydrochloric acid.

69

What is the chemical formula of nitric acid?

HNO3 is the chemical formula of nitric acid.

70

What is the chemical formula of ethanic acid?

CH3COOH is the chemical formula of ethanoic acid.

71

By what name is ethanoic acid also known?

Ethanoic acid isalso known by the name acetic acid.

72

What is the chemical formula of methanoic acid?

HCOOH is the chemical formula of methanoic acid.

73

By what name is methanoic acid also known?

Methanoic acid is also known by the name formic acid.

74

What is the chemical formula of citric acid?

C6H8O7 is the chemical formula of citric acid.

75

Where might you expect to find sulphuric acid outside of a lab?

Sulphuric acid is used in car batteries.

76

What happens when an acid is added to water?

When an acid is added to water, the acid releases H+ ions into solution.

77

What are the common bases?

  • metal oxides
  • metal hydroxides
  • ammonia
  • amines

78

Define an acid

An acid is a proton donor.

79

Define a base

A base is a proton acceptor.

80

What are common alkalis?

  • sodium hydroxide
  • potassium hydroxide
  • ammonia

81

TRUE or FALSE

Alkalis are very corrosive

TRUE!

Alkalis are very corrosive, in fact they are often more corrosive than acids.

82

Define an alkali

An alkali is a type of base that dissolves in water forming hydroxide ions (OH-).

83

What does amphoteric mean?

Amphoteric means having both properties of acids and bases.

84

Define a salt

A salt is a chemical compound formed from an acid when an Hion from the acid is replaced by a metal ion or another positive ion, such as the ammonium ion, NH4+.

85

Define a cation

A cation is a positively charged ion.

86

Define an anion.

An anion is a negatively charged ion.

87

What is a diproptic acid?

A diproptic acid has two replaceable protons.

88

What term is given to a diproptic acid when one of its protons has been replaced?

If one proton is replaced in a diproptic acid then an acid salt is formed.

89

TRUE or FALSE

A salt acid can behave as an acid?

TRUE!

A salt acid can behave as an acid.

90

acid + carbonate ⇒ ?

acid + carbonate ⇒ salt + CO2 + H2O

91

acid + base ⇒ ?

acid + base ⇒ salt + H2O

92

acid + alkali ⇒ ?

acid + alkali ⇒ salt + H2O

93

(reactive) metal + water ⇒ ?

(reactive) metal + water ⇒ salt + 

94

acid + aqueous ammonia ⇒ ?

acid + aqueous ammonia ⇒ ammonium salt

95

To what does the term hydrated apply in chemistry?

The term hydrated refers to a crystalline compound containing water molecules.

96

To what does the term anhydrous refer?

The term anhydrous refers to a substance that contains no water molecules.

97

To what does water of crystallisation refer?

Water of crystallisation refers to water molecules that form an essential part of the crystalline structure of a compound.

98

What identifies the end point of a titration?

The end point of a titration is identified by a colour change of an indicator.

99

What colour is methyl orange in acid?

In acid, methyl orange is red.

100

What colour is methyl orange in a base?

In a base, methyl orange is yellow.

101

What is the 'end point' colour of methyl orange in an acid-base titration?

The 'end point' colour of methyl orange in an acid-base titration is orange.

102

What colour is bromothymol blue in an acid?

In an acid, bromothymol blue is yellow.

103

What colour is bromothymol blue in a base?

In a base, bromothymol blue is blue.

104

What colour is bromothymol blue at the 'end point' of an acid-base titration?

At the 'end point' of an acid-base titration, bromothymol blue is green.

105

What colour is phenolphthalein in an acid?

In an acid, phenolphthalein is colourless.

106

What colour is phenolphthalein in a base?

In a base, phenolphthalein is pink.

107

What colour is phenolphthalein at the 'end point' of an acid-base titration?

Phenolphthalein is pale pink at the 'end point' of an acid-base titration.

108

Define oxidation number

An oxidation number is a measure of the number of electrons that an atom uses to bond with atoms of another element.

109

What is the oxidation number of an ucombined element?

An uncombined element has an oxidation number of 0.

110

What is the oxidation number of combined fluorine?

The oxidation number of combined fluorine is -1.

111

What is the oxidation number of combined oxygen?

Combined oxygen has an oxidation number of -2.

112

When does combined oxygen have an oxidation number of +2 instead of -2?

When oxygen is combined with fluorine, it has an oxidation number of +2 as opposed to -2.

113

What id the oxidatioon number of combined hydrogen?

The oxidation of combined hydrogen is +1.

114

When is the oxidation number of combined hydrogen not +1?

The oxidation number is not +1 and is -1 when it is in a metal hydride.

115

What is the oxidation number of hydrogen when it is found in a metal hydride?

The oxidation number of hydrogen in a metal hydride is -1.

116

What is the oxidation number of a simple ion?

The oxidation number of a simple ion is the charge on the ion.

117

Which groups tend to have varying oxidation numbers depending on what they're bound to?

The transition elements have variable oxidation numbers depending on what they're bound to.

118

What is an oxyanion?

Oxyanions are negative ions that contain an element along with oxygen.

119

What do the names of oxyanions usually end in?

The names of oxyanions usually end in -ate to indicate oxygen.

120

Does oxidation lead to an increase or decrease in oxidation number?

Oxidation leads to an increase in oxidation number.

121

Does reduction lead to an increase or a decrease in oxidation number?

Reduction leads to a decrease in oxidation number.

122

What is a redox reaction?

A redox reaction is one in which both reduction and oxidation take place.

123

What is a reducing agent?

A reducing agent is a reagent that reduces (adds electrons to) another species.

124

What is an oxidising agent?

An oxidising agent is a reagent that oxidises (takes electrons from) another species.

125

TRUE or FALSE

Metals tend to be oxidised

TRUE!

Metals tend to be oxidised - losing electrons to form positive ions.

126

TRUE or FALSE

Non-metals tend to be oxidised.

FALSE!

Non-metals tend to be reduced - gaining electrons to form negative ions.

127

Define the relative isotopic mass.

Relative isotopic mass is the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.