Atomic Structure and the Periodic Table Flashcards
1
Q
What are atoms?
A
Tiny particles of matter that are the building blocks of all matter
Atoms are made of subatomic particles: protons, neutrons, and electrons.
2
Q
Where are protons and neutrons located in an atom?
A
At the center of the atom, called the nucleus.
3
Q
What is the mass of an electron compared to protons and neutrons?
A
Negligible.
4
Q
What is a chemical symbol?
A
A representation of an element, consisting of one or two letters.
5
Q
What does an element consist of?
A
Atoms that all contain the same number of protons.
6
Q
What is the significance of the atomic number?
A
It represents the number of protons in an element.
7
Q
What is a compound?
A
A pure substance made up of two or more elements chemically combined.
8
Q
How can compounds be separated?
A
They cannot be separated by physical means.
9
Q
What is the chemical formula for water?
A
H2O.
10
Q
What is the difference between elements and compounds?
A
Elements are pure substances made of one type of atom, while compounds are made of two or more different atoms chemically combined.
11
Q
What are ionic compounds?
A
Compounds formed from metal and non-metal elements joined as particles called ions.
12
Q
What are covalent compounds?
A
Compounds that contain only non-metals.
13
Q
What must be true for a chemical equation to be balanced?
A
The same number of atoms of each element must be present on both sides.
14
Q
What is a common mistake when balancing equations?
A
Changing the small numbers in the chemical formula of a substance.
15
Q
What is a common mistake when balancing symbol equations?
A
Adding, changing, or removing small numbers in the chemical formula of a substance
This mistake alters the identity of the substance.
16
Q
What are half equations used for?
A
To show what happens to the electrons in reactions where atoms, molecules or ions are gaining or losing electrons.
17
Q
What are spectator ions?
A
Ions which are present but do not take part in reactions.
18
Q
What is a mixture?
A
A combination of two or more substances that are not chemically joined together.
19
Q
List the methods used for separating mixtures.
A
- Filtration
- Evaporation
- Distillation
- Chromatography
20
Q
What does filtration separate?
A
An insoluble solid from a mixture of the solid and a liquid.
21
Q
What is the purpose of crystallisation?
A
To separate a dissolved solid from a solution.
22
Q
What happens during simple distillation?
A
A liquid is separated from a solution or a pure liquid is separated from a mixture of liquids.
23
Q
What is fractional distillation used for?
A
To separate two or more liquids that are miscible with one another.
24
Q
What does paper chromatography separate?
A
Substances that have different solubilities in a given solvent.
25
What is the visual output of a chromatography run called?
Chromatogram.
26
What did John Dalton propose in his atomic theory?
* Matter is made of atoms
* Atoms of the same element are identical
* Different atoms combine to form new substances.
27
What is the plum pudding model?
A model that depicts negative electrons spread throughout soft globules of positively charged material.
28
What did Rutherford's gold foil experiment demonstrate?
Most of an atom's mass is concentrated in a region called the nucleus.
29
What is the nuclear model of the atom?
A model where the atom consists mainly of empty space with the nucleus at the center and electrons orbiting around it.
30
What did Niels Bohr propose about electrons?
Electrons orbit the nucleus in fixed shells or orbitals at set distances from the nucleus.
31
When was the neutron discovered?
In 1932 by James Chadwick.
32
What are the relative electrical charges of protons, neutrons, and electrons?
* Proton: +1
* Neutron: 0 (neutral)
* Electron: -1
33
What is the size of an atom?
Approximately 1 x 10^-10 metres or 0.1 nanometres.
34
What is the radius of the nucleus compared to the atom?
About 10,000 times smaller, approximately 1 x 10^-14 m.
35
What is the typical radius of an atom?
About 1 x 10^-10 metres or 0.1 nanometres
36
What does the nucleus of an atom contain?
Protons and neutrons only
37
How much smaller is the radius of the nucleus compared to the atom?
About 10,000 times smaller, around 1 x 10^-14 m
38
What is the mass comparison between protons, neutrons, and electrons?
1 proton has the same mass as around 1840 electrons
39
What is the atomic number of an atom?
The number of protons in the nucleus of an atom, symbolized by Z
40
True or False: The atomic number changes during a chemical reaction.
False
41
What is the mass number of an atom?
The total number of protons and neutrons in the nucleus, symbolized by A
42
What are isotopes?
Atoms of the same element with the same number of protons and electrons but different numbers of neutrons
43
How is an isotope denoted?
By the chemical symbol followed by a dash and the mass number, e.g., C-14
44
How do isotopes display their chemical characteristics?
They have the same number of electrons in their outer shells
45
What is the formula to calculate the number of neutrons in an atom?
Mass number (A) - Atomic number (Z)
46
What are the PEN numbers in atomic structure?
Protons, Electrons, Neutrons
47
What is the relative atomic mass (Ar)?
An average value that accounts for the abundance of isotopes of the element
48
What is the relative atomic mass unit based on?
1/12th the mass of a carbon-12 atom
49
How is the relative atomic mass calculated?
Using the formula: ( % of isotope A x mass of isotope A + % of isotope B x mass of isotope B + ... ) / 100
50
What is the electronic configuration of carbon?
2,4
51
How many electrons can the first shell hold?
2 electrons
52
How is the outermost shell of an atom referred to?
The valence shell
53
What is the electronic configuration of sodium?
2,8,1
54
What information does the last notation of electronic configuration provide?
The number of outer shell electrons
55
What is the electronic configuration for chlorine?
2,8,7
56
What is the electronic configuration of magnesium?
2,8,2
57
How many occupied shells does chlorine have?
3 occupied shells
58
Fill in the blank: The atomic number is equal to the number of _______ in an atom.
protons
59
True or False: Atoms are mostly filled with solid matter.
False
60
How are elements arranged on the periodic table?
In order of increasing atomic number
## Footnote
Each element has one proton more than the element preceding it.
61
What are the two main classifications of elements in the periodic table?
Metals and non-metals
62
What do the horizontal rows in the periodic table represent?
Periods, indicating the number of electron shells
63
What do the vertical columns in the periodic table represent?
Groups, indicating the number of outer electrons
64
What is the group number for elements with one outer electron?
Group 1 (Alkali Metals)
65
True or False: The atomic number of an element changes during chemical reactions.
False
66
What does the group number indicate about an element?
The number of electrons in the outer shell (valence electrons)
67
What is the exception to the group number rule regarding outer shell electrons?
Helium, which has only 2 electrons in its first shell
68
Who created the first draft of the periodic table in 1869?
Dmitri Mendeleev
69
Why did Mendeleev leave gaps in his periodic table?
To allow for undiscovered elements
70
What are isotopes?
Atoms of the same element with different numbers of neutrons
71
How do metals typically react in terms of electrons?
By losing electrons to form positive ions
72
What is the term for positive ions?
Cations
73
What is the term for negative ions?
Anions
74
What is the general trend in metallic character across a period?
Decreases from left to right
75
What are metalloids?
Elements that display properties of both metals and non-metals
76
What is the boiling point trend of noble gases as you move down the group?
Increases
77
What are the noble gases?
Non-metals, monatomic, colorless, and non-flammable gases
78
What is the electronic configuration of Argon?
2, 8, 8
79
What is a characteristic property of Group 1 elements?
They form alkaline solutions when they react with water
80
Fill in the blank: The first three alkali metals are ______, sodium, and potassium.
Lithium
81
What happens to the melting points of Group 1 metals as you move down the group?
They decrease
82
What is the reactivity trend of Group 1 metals?
Increases as you go down the group
83
What is the boiling point of helium?
-269 ºC
84
What is the unique feature of the noble gas helium compared to others in its group?
It has 2 electrons in its outer shell
85
What happens to the melting points of Group 1 elements as you move down the group?
Melting points decrease as you move down the group
## Footnote
This is due to decreasing attractive forces between outer electrons and positive ions.
86
How does the reactivity of Group 1 metals change as you go down the group?
Reactivity increases as you go down the group.
87
When a Group 1 element reacts, how many electrons do its atoms need to lose?
1 electron.
88
What type of ions are formed when Group 1 elements lose their outer electron?
1+ ions.
89
What configuration do Group 1 atoms achieve after losing their outer electron?
Noble gas configuration.
90
As you go down Group 1, what happens to the number of electron shells?
The number of shells increases by 1.
91
What effect does increasing distance from the nucleus have on the outermost electron?
Weaker forces of attraction between the outermost electron and the nucleus.
92
What happens to the energy required to remove the outer electron as you go down Group 1?
Less energy is required.
93
What is the general trend in the reactions of the first three alkali metals with water?
Reactions become more vigorous as you descend the group.
94
What is the reaction of lithium with water?
2Li (s) + 2H2O (l) → 2LiOH (aq) + H2 (g)
## Footnote
This reaction is relatively slow.
95
What is the reaction of sodium with water?
2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g).
96
What is the reaction of potassium with water?
2K (s) + 2H2O (l) → 2KOH (aq) + H2 (g).
97
What are the observations during the reaction of lithium with water?
Fizzing, lithium moves on the surface of the water.
98
What happens when rubidium, caesium, and francium react with air and water?
They react more vigorously than the first three alkali metals.
99
Which alkali metal is the least reactive?
Lithium.
100
What is formed when alkali metals react with oxygen?
Metal oxides.
101
What is the reaction of lithium with oxygen?
4Li (s) + O2 (g) → 2Li2O (s).
102
What is the reaction of sodium with oxygen?
4Na (s) + O2 (g) → 2Na2O (s).
103
What is the reaction of potassium with oxygen?
4K (s) + O2 (g) → 2K2O (s).
104
What do all Group 1 metals produce when they react with water?
Alkaline solutions (> pH 7).
105
What are the halogens in Group 7?
Fluorine, chlorine, bromine, iodine, and astatine.
106
What is the state and appearance of fluorine at room temperature?
Yellow gas.
107
What is the state and appearance of chlorine at room temperature?
Pale yellow-green gas.
108
What is the state and appearance of bromine at room temperature?
Red-brown liquid.
109
What is the state and appearance of iodine at room temperature?
Grey solid.
110
How does the boiling point of halogens change as you go down the group?
Boiling points increase.
111
What happens to the physical state of halogens as you descend the group?
Fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid.
112
What trend is observed in the reactivity of the halogens as you go down the group?
Reactivity decreases.
113
What do halogen atoms form when they gain an electron?
-1 ions called halide ions.
114
Which halogen is the most reactive?
Fluorine.
115
What is a halogen displacement reaction?
Occurs when a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide.
116
What happens when chlorine is added to potassium bromide solution?
A displacement reaction occurs, and the solution turns orange.
117
What happens when bromine is added to potassium iodide solution?
A displacement reaction occurs, and the solution turns brown.
118
What type of compounds do halogens form with metals?
Ionic compounds called metal halide salts.
119
What is formed when chlorine reacts with sodium?
Sodium chloride (NaCl).
120
What type of structures do halogens form with non-metals?
Simple molecular covalent structures.
121
What do halogens form when they react with hydrogen?
Hydrogen halides (e.g., hydrogen chloride).
122
Fill in the blank: The halogens decrease in reactivity moving ______ the group.
down.
123
What are the typical properties of transition metals?
They are lustrous, hard, strong, good conductors of heat and electricity, highly dense, and have high melting points
## Footnote
Transition metals can have more than one oxidation state.
124
How do transition metals differ from alkali metals in terms of ion formation?
Transition metals can form ions with variable charges, whereas alkali metals form ions with a +1 charge
## Footnote
Example: Iron can form Fe2+ or Fe3+ ions.
125
What are some common uses of transition metals as catalysts?
Iron in the Haber Process, Vanadium pentoxide (V2O5) in the Contact Process, Nickel in hydrogenation of alkenes
## Footnote
Catalysts speed up reactions without being used up.
126
What is the significance of titanium in medical applications?
It has high biocompatibility and can bond with bones
## Footnote
Useful in limb and joint replacements.
127
What is a characteristic of compounds formed by transition metals in different oxidation states?
They have different properties and colors in aqueous solutions.
128
True or False: Transition metals themselves display a range of colors.
False
## Footnote
It is the compounds they form that are colorful.
129
What are some industrial uses of transition metals?
Forming colored compounds in dyes and paints, creating stained glass, making jewelry, and producing anti-corrosive materials.
130
What is a key difference in reactivity between transition metals and alkali metals?
Transition metals are much less reactive than alkali metals, which react vigorously with water, oxygen, and halogens.
131
Fill in the blank: Transition metals can lose a different number of _______ depending on their chemical environment.
electrons
132
What is the melting point of titanium?
1,688 ºC
133
What are the typical properties of alkali metals compared to transition metals?
Alkali metals are very soft and light, while transition metals are harder, stronger, and denser.
134
Why do scandium and zinc not qualify as transition metals?
They do not form colored compounds and have only one oxidation state.
135
How long can it take for iron to react with oxygen to form rust?
Several weeks
## Footnote
Requires the presence of water.
