Atomic Structure And Isotopes Flashcards
(158 cards)
1
Q
What is the atomic number of carbon?
A
6
2
Q
True or False: The molar mass of water (H2O) is approximately 18 g/mol.
A
True
3
Q
Fill in the blank: The three subatomic particles are protons, neutrons, and __________.
A
electrons
4
Q
What is the formula for calculating the number of moles?
A
Number of moles = mass (g) / molar mass (g/mol)
5
Q
What is the main component of an atom’s nucleus?
A
Protons and neutrons
6
Q
Which element has the chemical symbol ‘Na’?
A
Sodium
7
Q
True or False: Anions are negatively charged ions.
A
True
8
Q
What is the pH of a neutral solution at 25°C?
A
7
9
Q
What is the term for the energy required to break a bond?
A
Bond dissociation energy
10
Q
What is the process of a solid turning directly into a gas called?
A
Sublimation
11
Q
What is Avogadro’s number?
A
6.022 x 10^23
12
Q
In a chemical reaction, the substances that are present before the reaction are called __________.
A
reactants
13
Q
What is the term for the amount of energy required to raise the temperature of 1 gram of substance by 1°C?
A
Specific heat capacity
14
Q
What is the formula for calculating concentration?
A
Concentration (mol/dm³) = moles of solute / volume of solution (dm³)
15
Q
True or False: A catalyst is a substance that increases the rate of a chemical reaction without being consumed.
A
True
16
Q
What is the main gas produced during photosynthesis?
A
Oxygen
17
Q
What does the term ‘oxidation’ refer to in a chemical reaction?
A
The loss of electrons
18
Q
What is the primary type of bonding in sodium chloride (NaCl)?
A
Ionic bonding
19
Q
Fill in the blank: An acid is a substance that donates __________.
A
protons (H+ ions)
20
Q
What is the empirical formula of glucose (C6H12O6)?
A
CH2O
21
Q
What is the term for the temperature at which a liquid turns into a gas?
A
Boiling point
22
Q
True or False: Noble gases are highly reactive.
A
False
23
Q
What is the name of the process by which a liquid turns into vapor?
A
Evaporation
24
Q
What is the octet rule?
A
Atoms tend to gain, lose, or share electrons to achieve a full outer shell of eight electrons.
25
What type of reaction is represented by the equation A + B → AB?
Synthesis reaction
26
What is the term for the minimum energy required for a reaction to occur?
Activation energy
27
What is a saturated solution?
A solution in which no more solute can dissolve at a given temperature.
28
True or False: Ionic compounds typically have high melting and boiling points.
True
29
What is the difference between strong and weak acids?
Strong acids completely dissociate in solution, while weak acids only partially dissociate.
30
What is the process called where a liquid changes to a solid?
Freezing
31
What are isotopes?
Atoms of the same element with different numbers of neutrons.
32
What is the standard unit of pressure in chemistry?
Atmosphere (atm) or Pascal (Pa)
33
Fill in the blank: The __________ is the part of the atom that contains protons and neutrons.
nucleus
34
What is the effect of increasing temperature on the rate of a chemical reaction?
It generally increases the rate of reaction.
35
What does the term 'solubility' refer to?
The ability of a substance to dissolve in a solvent.
36
What is the formula for calculating the percentage yield of a reaction?
Percentage yield = (actual yield / theoretical yield) x 100%
37
True or False: A base is a substance that accepts protons.
True
38
What is the main component of air?
Nitrogen
39
What is the chemical formula for sulfuric acid?
H2SO4
40
What is the difference between endothermic and exothermic reactions?
Endothermic reactions absorb heat, while exothermic reactions release heat.
41
What does a high pH indicate about a solution?
It is basic (alkaline).
42
What is the term for the process of a gas turning into a liquid?
Condensation
43
What is the primary type of bonding in metals?
Metallic bonding
44
Fill in the blank: The __________ is the measure of how much solute is present in a given volume of solvent.
concentration
45
What is the significance of the mole concept in chemistry?
It allows chemists to count quantities of atoms and molecules in a practical way.
46
True or False: A chemical change involves the formation of new substances.
True
47
What is the formula for calculating the number of atoms in a mole?
Number of atoms = moles x Avogadro's number
48
What is the term for a mixture in which the composition is uniform throughout?
Homogeneous mixture
49
What is the chemical formula for ammonia?
NH3
50
What is the process called when a solid turns into a gas without becoming liquid?
Sublimation
51
What is a covalent bond?
A bond formed by the sharing of electrons between atoms.
52
Fill in the blank: The __________ of an element is determined by the number of protons in its nucleus.
atomic number
53
What is the role of a buffer solution?
To maintain a stable pH when small amounts of acid or base are added.
54
What is the term for the change from liquid to gas at any temperature?
Evaporation
55
What is an oxidizing agent?
A substance that gains electrons in a redox reaction.
56
True or False: The law of conservation of mass states that mass can be created or destroyed in a chemical reaction.
False
57
What is the main product of the combustion of hydrocarbons?
Carbon dioxide and water
58
What is the chemical formula for hydrochloric acid?
HCl
59
What is the significance of the Gibbs free energy?
It indicates the spontaneity of a reaction.
60
Fill in the blank: The __________ is the energy change that occurs during a chemical reaction.
enthalpy change
61
What is the purpose of titration in chemistry?
To determine the concentration of a solution.
62
What is the formula for calculating the molarity of a solution?
Molarity (mol/L) = moles of solute / liters of solution
63
What is a redox reaction?
A reaction that involves the transfer of electrons between two species.
64
True or False: Acids turn blue litmus paper red.
True
65
What is the term for a substance that speeds up a reaction without being consumed?
Catalyst
66
What is the primary type of reaction in which an acid reacts with a base?
Neutralization reaction
67
What is the term for the energy stored in chemical bonds?
Chemical potential energy
68
Fill in the blank: The __________ is the amount of solute dissolved in a given volume of solvent.
concentration
69
What is the role of enzymes in biological reactions?
To act as catalysts that speed up the reactions.
70
What is the main type of bonding in water (H2O)?
Covalent bonding
71
What is the term for the pressure exerted by a vapor in equilibrium with its liquid?
Vapor pressure
72
True or False: A saturated solution contains more solute than a supersaturated solution.
False
73
What is the formula for calculating the heat change in a reaction?
q = mcΔT
74
What is the primary purpose of chromatography?
To separate mixtures into their individual components.
75
What is the main gas produced during cellular respiration?
Carbon dioxide
76
What is the term for the maximum amount of solute that can dissolve in a given amount of solvent?
Solubility limit
77
Fill in the blank: __________ is the process of a liquid turning into vapor.
Evaporation
78
What is the chemical formula for acetic acid?
CH3COOH
79
What does a low pH indicate about a solution?
It is acidic.
80
What is the primary type of reaction in which two or more substances combine to form a single product?
Synthesis reaction
81
What is the term for the amount of a substance in a given volume of solution?
Concentration
82
True or False: The boiling point of a substance decreases with increasing atmospheric pressure.
False
83
What is the chemical formula for potassium nitrate?
KNO3
84
What is the term for a reaction that releases energy, usually in the form of heat?
Exothermic reaction
85
What is the primary type of bonding in diamond?
Covalent bonding
86
Fill in the blank: The __________ is the energy required to break a bond between two atoms.
bond dissociation energy
87
What is the term for the temperature at which a solid turns into a liquid?
Melting point
88
True or False: All isotopes of an element have the same chemical properties.
True
89
What is the basic unit of matter?
Atom
90
What are the three primary subatomic particles?
Protons, neutrons, and electrons
91
What charge do protons carry?
Positive charge
92
What charge do electrons carry?
Negative charge
93
What is the charge of a neutron?
No charge (neutral)
94
Where are protons and neutrons located in an atom?
In the nucleus
95
Where are electrons located in an atom?
In electron shells around the nucleus
96
What is the atomic number of an element?
The number of protons in the nucleus
97
What is the mass number of an atom?
The total number of protons and neutrons
98
Define isotopes.
Atoms of the same element with the same number of protons but different numbers of neutrons
99
True or False: Isotopes have different chemical properties.
False
100
What is the relative atomic mass?
The weighted average mass of an atom of an element compared to 1/12 of carbon-12
101
What is a cation?
A positively charged ion
102
What is an anion?
A negatively charged ion
103
Fill in the blank: The nucleus contains ______ and ______.
Protons and neutrons
104
What is the significance of the electron configuration?
It determines the chemical properties of an element
105
What does the term 'valence electrons' refer to?
Electrons in the outermost shell
106
How many electrons can the first shell hold?
2 electrons
107
How many electrons can the second shell hold?
8 electrons
108
What is the principle of electron configuration?
Electrons fill orbitals starting from the lowest energy level to the highest
109
What is a stable isotope?
An isotope that does not undergo radioactive decay
110
What is a radioactive isotope?
An isotope that is unstable and decays over time
111
True or False: All isotopes of an element are radioactive.
False
112
What is the term for the process by which an unstable nucleus loses energy?
Radioactive decay
113
What is the half-life of a radioactive isotope?
The time taken for half of the radioactive nuclei to decay
114
What is the formula for calculating the number of remaining nuclei after n half-lives?
N = N0 / (2^n)
115
Define 'ionization energy'.
The energy required to remove an electron from an atom or ion
116
What trend does ionization energy generally show across a period?
It increases across a period
117
What trend does ionization energy generally show down a group?
It decreases down a group
118
What is an electron shell?
A region around the nucleus where electrons are likely to be found
119
What is the maximum number of electrons in the third shell?
18 electrons
120
True or False: Electrons in the same shell have the same energy level.
True
121
What are the four types of orbitals?
s, p, d, and f orbitals
122
How many electrons can an s orbital hold?
2 electrons
123
How many electrons can a p orbital hold?
6 electrons
124
How many electrons can a d orbital hold?
10 electrons
125
How many electrons can an f orbital hold?
14 electrons
126
What is the Pauli Exclusion Principle?
No two electrons in an atom can have the same set of four quantum numbers
127
What is Hund's Rule?
Electrons will occupy degenerate orbitals singly before pairing up
128
What is the significance of quantum numbers?
They describe the properties of atomic orbitals and the electrons in them
129
What are the four quantum numbers?
Principal, azimuthal, magnetic, and spin quantum numbers
130
What does the principal quantum number (n) indicate?
The energy level and size of the orbital
131
What does the azimuthal quantum number (l) indicate?
The shape of the orbital
132
What does the magnetic quantum number (m) indicate?
The orientation of the orbital in space
133
What does the spin quantum number (s) indicate?
The direction of the electron's spin
134
True or False: The atomic mass is always a whole number.
False
135
What is the significance of the atomic mass unit (amu)?
It is a standard unit of mass used to express atomic and molecular weights
136
What is the formula for calculating the average atomic mass of an element with multiple isotopes?
Average atomic mass = Σ (fractional abundance × mass of isotope)
137
What is a stable nucleus?
A nucleus that has a balanced ratio of protons to neutrons
138
What is the neutron-to-proton ratio for stable isotopes?
Close to 1:1 for lighter elements, and increases for heavier elements
139
What is beta decay?
A type of radioactive decay in which a beta particle (electron or positron) is emitted
140
What is alpha decay?
A type of radioactive decay in which an alpha particle (2 protons and 2 neutrons) is emitted
141
What is gamma decay?
A type of radioactive decay that involves the emission of gamma radiation
142
What happens to the atomic number during beta decay?
It increases by 1
143
What happens to the atomic number during alpha decay?
It decreases by 2
144
What is a positron?
The antiparticle of an electron with a positive charge
145
What is a neutron?
A subatomic particle found in the nucleus with no charge
146
What is the significance of stable isotopes in medicine?
They are used in diagnostic imaging and treatment
147
What is the role of isotopes in carbon dating?
They help determine the age of organic materials based on the decay of carbon-14
148
Fill in the blank: The number of protons defines the ______ of an element.
Element
149
What is the concept of atomic mass weighted average?
It accounts for the abundance of each isotope in nature
150
What does the term 'nucleon' refer to?
Any subatomic particle found in the nucleus (proton or neutron)
151
What is the significance of electron affinity?
It measures the energy change when an electron is added to a neutral atom
152
What is the trend of electron affinity across a period?
It generally increases across a period
153
What is the trend of electron affinity down a group?
It generally decreases down a group
154
True or False: Atoms can gain or lose protons.
False
155
What is an example of a common isotope used in medicine?
Technetium-99m
156
What is the significance of the octet rule?
Atoms tend to gain, lose, or share electrons to achieve a full outer shell
157
What is ionization?
The process of removing an electron from an atom or molecule
158
What is the difference between atomic mass and mass number?
Atomic mass is the weighted average of isotopes, while mass number is the total number of protons and neutrons
