Structure Of Molecules Flashcards
1
Q
What force keeps atoms together in substances?
A
Chemical bond
2
Q
Which elements exist as atoms?
A
All elements except noble gases
3
Q
What are molecules of the same element made of?
A
The same kind of atoms (e.g., O₂, H₂)
4
Q
What is the process called when atoms combine with one another?
A
Chemical bonding
5
Q
Why do atoms form chemical bonds?
A
To decrease their energy and attain stability
6
Q
Atoms tend to increase their energy by combining with other atoms. (True/False)
A
False
7
Q
All atoms can form chemical bonds to become stable. (True/False)
A
True
8
Q
What does the valence concept state?
A
B) Atoms combine by losing, gaining, or sharing electrons
9
Q
In the Octet theory of valence, how many electrons do atoms try to have in their outermost shell?
A
Eight
10
Q
Which noble gas has only two electrons in its outermost shell?
A
Helium (He)
11
Q
Which rule explains the tendency of atoms to have eight electrons in their outermost shell for stability?
A
Octet Rule
12
Q
Atoms of which group in the periodic table are called noble gases?
A
Group VIII
13
Q
What is the other name for noble gases?
A
Inert gases
14
Q
Helium, Neon, and Argon have how many electrons in their outermost shell?
A
Eight
15
Q
Atoms of noble gases are very stable because they have a full outer shell. (True/False)
A
True
16
Q
How many electrons does Helium have in its outermost shell?
A
Two
17
Q
How many electrons does the outermost shell of noble gases have?
A
Eight (except Helium, which has two)
18
Q
Why do atoms tend to form chemical bonds?
A
To complete eight electrons in their outermost shell to attain the noble gas configuration
19
Q
What is the concept where atoms combine by sharing electrons to complete their outermost shell?
A
The Octet Rule
20
Q
Which orbitals overlap to form a sigma bond?
A
Endwise overlapping
21
Q
Which orbitals overlap to form a pi bond?
A
Sidewise overlapping
22
Q
What are the electrons involved in bond formation called?
A
Bonding electrons
23
Q
What is the outermost shell of an atom where loss, gain, or sharing of electrons takes place called?
A
Valence shell
24
Q
Which electrons do not take part in bonding?
A
Non-bonding electrons
25
In a chemical reaction, what happens to the bonds between elements?
The bonds are rearranged
26
How many types of bonds are there?
Four
27
Which bond is formed due to the complete transfer of electrons between atoms?
Ionic bond
28
What is the force that holds atoms together in an ionic bond called?
Electrostatic force of attraction
29
Which type of bond is formed between a metal and a non-metal?
Ionic bond
30
What does a metal atom do to form a cation?
It loses electrons
31
What does a non-metal atom do to form an anion?
It gains electrons
32
What is the formation of Sodium Chloride (NaCl) an example of?
Ionic bond formation
33
Sodium (Na) has one electron in its outermost shell. What does it do to achieve stability?
It loses one electron to form a cation (Na⁺)
34
Chlorine (Cl) has seven electrons in its outermost shell. What does it do to achieve stability?
It gains one electron to form an anion (Cl⁻)
35
Which element forms a cation in the formation of Sodium Chloride?
Sodium (Na)
36
Which element forms an anion in the formation of Sodium Chloride?
Chlorine (Cl)
37
Opposite charges between ions attract each other. (True/False)
True
38
What is the result of the ionic bond formation between Na⁺ and Cl⁻?
Sodium Chloride (NaCl)
39
Which atoms are involved in the formation of Sodium Chloride (NaCl)?
Sodium (Na) and Chlorine (Cl)
40
In ionic bonding, what is formed when atoms lose or gain electrons?
Ions
41
Which force keeps the ions together in an ionic bond?
Electrostatic force of attraction
42
How does Sodium achieve the electronic configuration of Neon?
By losing one electron to form a cation (Na⁺)
43
How does Chlorine achieve the electronic configuration of Argon?
By gaining one electron to form an anion (Cl⁻)
44
What is the electron configuration of a neutral Sodium (Na) atom?
11 protons and 11 electrons
45
What happens to Sodium (Na) when it loses an electron?
It becomes a Sodium ion (Na⁺) with 10 electrons
46
How many electrons does Chlorine (Cl) need to complete its outer shell?
One electron
47
What happens to Chlorine (Cl) when it gains an electron?
It becomes a Chloride ion (Cl⁻) with 18 electrons
48
What type of bond is formed between Sodium (Na) and Chlorine (Cl)?
Ionic bond
49
What is formed when Sodium (Na) loses one electron and Chlorine (Cl) gains one electron?
Sodium Chloride (NaCl)
50
How many electrons does Sodium (Na) have in its outer shell after it becomes a Sodium ion?
Eight electrons
51
How does Chlorine (Cl) achieve the electronic configuration of Argon?
By gaining one electron to form a chloride ion (Cl⁻)
52
In the formation of Calcium Chloride (CaCl₂), how many electrons does Calcium (Ca) lose?
Two electrons
53
How many electrons does Calcium (Ca) need to lose to achieve the electronic configuration of Neon?
Two electrons
54
What is the result when Calcium (Ca) loses two electrons and Chlorine (Cl) gains one electron?
Calcium Chloride (CaCl₂)
55
How many chloride ions are needed to combine with one Calcium ion to form Calcium Chloride (CaCl₂)?
Two chloride ions
56
Magnesium (Mg) loses two electrons to form which ion?
Magnesium ion (Mg²⁺)
57
What is the electronic configuration of a Magnesium (Mg) ion?
2, 8
58
Which elements form ionic bonds with Chlorine (Cl)?
Metals
59
What type of bond is formed between a metal and a non-metal?
Ionic bond
60
Magnesium chloride (MgCl₂) is formed from which elements?
Magnesium (Mg) and Chlorine (Cl)
61
How many electrons does Magnesium (Mg) lose to form a magnesium ion (Mg²⁺)?
Two electrons
62
What is the formula for Magnesium Chloride?
MgCl₂
63
How many electrons does Lithium (Li) have in its outermost shell?
One electron
64
How many electrons does Oxygen (O) need to complete its outer shell?
Two electrons
65
What is the result when Lithium (Li) and Oxygen (O) combine to form a compound?
Lithium Oxide (Li₂O)
66
True or False: Sodium (Na) becomes stable by losing one electron. (True/False)
True
67
True or False: Chlorine (Cl) becomes stable by losing one electron. (True/False)
False
68
True or False: Calcium (Ca) forms a divalent ion. (True/False)
True
69
Fill in the blank: Magnesium (Mg) and Chlorine (Cl) form ________ bond to produce Magnesium Chloride (MgCl₂).
Ionic
70
Fill in the blank: The formula for the Ionic compound formed between Calcium (Ca) and Chlorine (Cl) is ________.
CaCl₂
71
Which two elements are involved in the formation of Sodium Chloride (NaCl)?
Sodium (Na) and Chlorine (Cl)
72
How many chloride ions (Cl⁻) are needed to balance the charge of one calcium ion (Ca²⁺)?
Two chloride ions
73
What is the bond type between Magnesium (Mg) and Oxygen (O)?
Ionic bond
74
How many electrons does Fluorine (F) need to gain to complete its outer shell?
One electron
75
Draw the ionic bond formation for Magnesium Oxide (MgO).
Magnesium loses two electrons, Oxygen gains two electrons, forming Mg²⁺ and O²⁻.
76
Which elements form a covalent bond in water (H₂O)?
Hydrogen and Oxygen
77
What is a covalent bond?
A covalent bond is formed when two atoms share electrons to attain stable electronic configurations.
78
Which types of elements generally form covalent bonds?
Non-metals
79
True or False: Covalent bonds are typically formed between metals. (True/False)
False
80
What is the formula of the molecule formed by two hydrogen atoms?
H₂
81
How is the shared pair of electrons in a covalent bond represented?
By a dash (—) between the two bonded atoms.
82
What is the name of the bond formed when two hydrogen atoms share electrons?
Covalent bond
83
Fill in the blank: A covalent bond is formed when two atoms are joined by ________.
sharing of electrons
84
In the molecule H₂, how many electrons are shared between the two hydrogen atoms?
Two electrons
85
What is the bond type between two hydrogen atoms in a molecule of hydrogen (H₂)?
Covalent bond
86
Which molecule is formed when two hydrogen atoms share electrons?
Hydrogen molecule (H₂)
87
What type of bond is formed in the molecule HCl?
Single covalent bond
88
What is represented by a single line (—) in a covalent bond?
A single covalent bond where two atoms share one pair of electrons.
89
How many types of covalent bonds are there?
Three types
90
Which of the following elements commonly form covalent bonds? (Hydrogen, Sodium, Oxygen, Calcium)
Hydrogen and Oxygen
91
True or False: A covalent bond always involves the transfer of electrons. (True/False)
False
92
Draw the electron dot and cross diagram for H₂. Label the shared pair of electrons.
Two hydrogen atoms, each sharing one electron, forming a bond.
93
Which of the following is a correct example of a single covalent bond? (H₂, NaCl, MgO)
H₂
94
Fill in the blank: The bond formed between hydrogen atoms in the molecule H₂ is a ________ bond.
Single covalent
95
What is the bond formed when two atoms share one electron each to form a pair of electrons?
Single covalent bond
96
True or False: A single covalent bond involves the sharing of two electrons. (True/False)
True
97
In the molecule HCl, what type of bond is formed between hydrogen and chlorine?
Single covalent bond
98
Draw the electron dot and cross diagram for H₂O (water). Label the single bond and the lone pairs.
Oxygen shares electrons with two hydrogen atoms to form a water molecule.
99
Which of the following is NOT a type of covalent bond? (Single covalent, Double covalent, Ionic bond)
Ionic bond
100
How many types of covalent bonds exist?
Three
101
Fill in the blank: A single covalent bond is formed when two atoms share ________ electrons.
One pair of electrons
102
What is the electronic configuration of a chlorine atom?
2, 8, 7
103
How does a chlorine molecule (Cl₂) form?
Two chlorine atoms share one electron each to form a molecule.
104
True or False: Chlorine atoms form a molecule by sharing two electrons. (True/False)
False
105
How many electrons does a chlorine atom have in its valence shell?
Seven electrons
106
Fill in the blank: Chlorine atoms share one electron each to form a ________ bond.
Covalent bond
107
What is the atomic number of carbon?
6
108
How is a methane molecule (CH₄) formed?
Carbon shares four electrons with four hydrogen atoms to form a molecule.
109
Which element shares electrons with hydrogen atoms to form methane (CH₄)?
Carbon
110
True or False: A methane molecule is formed when carbon shares electrons with four hydrogen atoms. (True/False)
True
111
Fill in the blank: In methane (CH₄), carbon needs ________ electrons to complete its octet.
Four
112
What is the bond type in the formation of the oxygen molecule (O₂)?
Double covalent bond
113
How many electrons does an oxygen atom need to complete its octet?
Two electrons
114
True or False: Oxygen atoms share two electrons each to form a double covalent bond. (True/False)
True
115
Draw the electron dot and cross diagram for the oxygen molecule (O₂).
Oxygen shares two electrons with another oxygen atom to form a molecule.
116
How many electrons does a carbon atom share in the formation of carbon dioxide (CO₂)?
Four electrons
117
What type of bond is formed in carbon dioxide (CO₂)?
Double covalent bond
118
How many oxygen atoms are involved in the formation of carbon dioxide (CO₂)?
Two oxygen atoms
119
True or False: Carbon dioxide (CO₂) involves single covalent bonds between carbon and oxygen. (True/False)
False
120
Fill in the blank: In carbon dioxide (CO₂), carbon forms ________ bonds with two oxygen atoms.
Double covalent
121
Which molecule is formed when carbon shares four electrons with two oxygen atoms?
Carbon dioxide (CO₂)
122
Draw the electron dot and cross diagram for carbon dioxide (CO₂).
Carbon shares four electrons with two oxygen atoms to form two double covalent bonds.
123
Multiple Choice: Which of the following molecules involves a double covalent bond? (O₂, H₂, CH₄)
O₂
124
Multiple Choice: In the formation of methane (CH₄), what does carbon share electrons with? (Oxygen, Hydrogen, Nitrogen)
Hydrogen
125
Why do atoms form chemical bonds?
To lower their energy and achieve a stable state.
126
What is the Octet Rule?
Atoms tend to attain eight electrons in their outermost shell to achieve stability.
127
What is a Triple Covalent Bond?
A bond in which two atoms share three electrons each, forming a total of six shared electrons.
128
Which of the following atoms tend to achieve a stable electron configuration by sharing electrons?
A) Oxygen
129
What type of bond is formed when two atoms share three electrons each?
C) Triple Bond
130
A Triple Covalent Bond is formed when two atoms share ____ electrons each.
131
The Octet Rule is achieved when an atom has ____ electrons in its outermost shell.
132
Atoms always form bonds to increase their energy.
False
133
Helium is stable with two electrons in its outer shell.
True
134
What is a covalent bond?
A bond where electrons are shared between atoms to achieve stability.
135
What happens when atoms form bonds?
They lower their energy and attain stability.
136
What is a dative bond?
A covalent bond where one atom donates both electrons to form a bond.
137
What is the Lewis structure of water?
H₂O with two lone pairs of electrons on oxygen and shared pairs between oxygen and hydrogen.
138
What happens when nitrogen in NH₃ donates a lone pair of electrons?
A) Forms a dative bond
139
In a dative bond
Covalent bond is formed
140
A dative bond is also called a ____ covalent bond.
141
The Lewis structure of H₂S is H-S-H
2
142
The Nitrogen atom in NH₃ is electron deficient.
False
143
The Boron atom in BCl₃ is electron deficient.
True
144
What is a Lewis structure?
A diagram representing shared and unshared electrons in a molecule.
145
What does a coordinate covalent bond involve?
A bond where one atom donates both electrons.
146
What is a non-polar covalent bond?
A covalent bond formed by the mutual sharing of electrons between atoms with similar electronegativities.
147
What is a polar covalent bond?
A covalent bond formed between atoms with different electronegativities, resulting in partial positive and negative charges.
148
Which molecule forms a polar covalent bond?
A) H₂O
149
In a polar covalent bond
D) Not shared at all
150
A non-polar covalent bond is formed when atoms have ____ electronegativities.
151
In a polar covalent bond
partially negative
152
In a non-polar covalent bond
153
The shared electrons in a polar covalent bond are equally shared between the atoms.
False
154
What is a polar covalent bond?
A bond with unequal sharing of electrons, creating partial charges on the atoms.
155
Give an example of a non-polar covalent bond.
Molecules like H₂, Cl₂, and O₂ form non-polar covalent bonds.
156
What is the shape of a carbon dioxide (CO2) molecule?
A) Linear
157
What is the bond angle in a water (H2O) molecule?
A) 104.5°
158
Which molecule has a trigonal pyramidal shape?
C) NH3
159
Which of the following molecules has a bent shape?
A) SO2
160
The intermolecular forces are __________ times weaker than the covalent bond.
25
161
Hydrogen bonding occurs when hydrogen is covalently bonded to __________.
All of the above
162
Intermolecular forces are much weaker in liquid water than in solid water.
False
163
Dipole-dipole interactions occur due to the attraction between the positive and negative poles of polar molecules.
True
164
The shape of the methane molecule (CH4) is tetrahedral.
True
165
Hydrogen chloride (HCl) is a non-polar molecule.
False
166
Which type of bond involves the sharing of electrons between atoms with similar electronegativities?
B) Non-Polar Covalent Bond
167
What happens to the electrons in metallic bonding?
C) Electrons move freely between atoms
168
In which of the following molecules does a polar covalent bond occur?
B) H2O
169
Which of the following is an example of an ionic bond?
A) NaCl
170
The bond formed when atoms share electrons equally is called a __________ bond.
Non-Polar Covalent
171
A molecule of water (H2O) contains a __________ covalent bond.
Polar
172
In a non-polar covalent bond, the electrons are shared equally.
True
173
In metallic bonding, electrons are localized and do not move freely.
False
174
The shape of a methane molecule (CH4) is tetrahedral.
True
175
In an ionic bond, electrons are shared equally between atoms.
False
176
What is the shape of a carbon dioxide (CO2) molecule?
"Linear"
177
What is the bond angle in a water (H2O) molecule?
"104.5°"
178
Which molecule has a trigonal pyramidal shape?
"NH3"
179
Which of the following molecules has a bent shape?
"SO2"
180
The intermolecular forces are __________ times weaker than the covalent bond.
"25"
181
Hydrogen bonding occurs when hydrogen is covalently bonded to __________.
"All of the above"
182
Intermolecular forces are much weaker in liquid water than in solid water.
"False"
183
Dipole-dipole interactions occur due to the attraction between the positive and negative poles of polar molecules.
"True"
184
The shape of the methane molecule (CH4) is tetrahedral.
"True"
185
Hydrogen chloride (HCl) is a non-polar molecule.
"False"
186
Which type of bond involves the sharing of electrons between atoms with similar electronegativities?
"Non-Polar Covalent Bond"
187
What happens to the electrons in metallic bonding?
"Electrons move freely between atoms"
188
In which of the following molecules does a polar covalent bond occur?
"H2O"
189
Which of the following is an example of an ionic bond?
"NaCl"
190
The bond formed when atoms share electrons equally is called a __________ bond.
"Non-Polar Covalent"
191
A molecule of water (H2O) contains a __________ covalent bond.
"Polar"
192
In a non-polar covalent bond, the electrons are shared equally.
"True"
193
In metallic bonding, electrons are localized and do not move freely.
"False"
194
The shape of a methane molecule (CH4) is tetrahedral.
"True"
195
In an ionic bond, electrons are shared equally between atoms.
"False"Question
196
How strong is a hydrogen bond compared to a covalent bond?
"Hydrogen bond is about twenty times weaker than a covalent bond
197
Is the hydrogen bond directional?
"Yes
198
What does hydrogen bonding help in the formation of?
"Hydrogen bonding helps in the formation of networks of molecules."
199
What are the properties of ionic compounds?
"Ionic compounds are solid at room temperature
200
What is the structure of ionic compounds?
"Ionic compounds are composed of cations and anions in crystalline form."
201
What happens to the melting point of an ionic compound with greater charges on the ions?
"The melting point increases. For example
202
How are covalent compounds formed?
"Covalent compounds are formed by the sharing of electrons between atoms."
203
Do covalent compounds have high or low melting and boiling points?
"Covalent compounds have low melting and boiling points."
204
Are covalent compounds electrolytes in solution?
"No
205
Are covalent bonds directional?
"Yes
206
What is the structure of covalent compounds?
"Covalent compounds are composed of molecules."
207
How do the reactions of covalent compounds compare to ionic compounds?
"Reactions of covalent compounds are slower than those of ionic compounds."
208
Are polar covalent compounds soluble in polar solvents?
"Yes
209
Are nonpolar covalent compounds soluble in nonpolar solvents?
"Yes
210
What type of bond holds metals together?
"Metals are held together by metallic bonds."
211
Are metals solid at room temperature?
"All metals are solid at room temperature and pressure
212
Can metals be shaped?
"Yes
213
Do metals conduct heat and electricity?
"Yes
214
Are metals shiny?
"Yes
215
Do metals produce specific sounds when struck?
"Yes
216
MCQ
What is the shape of a carbon dioxide (CO2) molecule?
217
MCQ
What is the bond angle in a water (H2O) molecule?
218
MCQ
Which molecule has a trigonal pyramidal shape?
219
MCQ
Which of the following molecules has a bent shape?
220
Fill-in-the-Blank
The intermolecular forces are __________ times weaker than the covalent bond.
221
Fill-in-the-Blank
Hydrogen bonding occurs when hydrogen is covalently bonded to __________.
222
True/False
Intermolecular forces are much weaker in liquid water than in solid water.
223
True/False
Dipole-dipole interactions occur due to the attraction between the positive and negative poles of polar molecules.
224
True/False
The shape of the methane molecule (CH4) is tetrahedral.
225
True/False
Hydrogen chloride (HCl) is a non-polar molecule.
226
MCQ
Which type of bond involves the sharing of electrons between atoms with similar electronegativities?
227
MCQ
What happens to the electrons in metallic bonding?
228
MCQ
In which of the following molecules does a polar covalent bond occur?
229
MCQ
Which of the following is an example of an ionic bond?
230
Fill-in-the-Blank
The bond formed when atoms share electrons equally is called a __________ bond.
231
Fill-in-the-Blank
A molecule of water (H2O) contains a __________ covalent bond.
232
True/False
In a non-polar covalent bond, the electrons are shared equally.
233
True/False
In metallic bonding, electrons are localized and do not move freely.
234
True/False
The shape of a methane molecule (CH4) is tetrahedral.
235
True/False
In an ionic bond, electrons are shared equally between atoms.
236
MCQ
An atom with a charge is called:
237
MCQ
Valence electrons are represented by:
238
MCQ
An element X is in group VI of the periodic table. The ion will be:
239
MCQ
Which pair of elements will join to form a compound with one-to-one ratio?
240
MCQ
When a calcium atom becomes a calcium ion (Ca²⁺):
241
MCQ
Fluorine and oxygen will form:
242
MCQ
Which two elements will form a covalent compound?
243
MCQ
In the formation of an ionic bond, the atoms taking part:
244
MCQ
Fluorine has an electronic configuration 2,7, and Oxygen has 2,6. The formula for the compound formed will be:
245
MCQ
Which of these statements about covalent bonds is incorrect?
