Podcast
Questions and Answers
What trend does electron gain enthalpy generally follow across a period?
What trend does electron gain enthalpy generally follow across a period?
- It becomes less negative.
- It becomes more positive.
- It becomes more negative. (correct)
- It stays constant.
Which element is expected to have the most negative electron gain enthalpy?
Which element is expected to have the most negative electron gain enthalpy?
- Oxygen
- Fluorine
- Phosphorus
- Chlorine (correct)
How does electron gain enthalpy change within a group as atomic size increases?
How does electron gain enthalpy change within a group as atomic size increases?
- It becomes more positive.
- It becomes more negative.
- It remains the same.
- It becomes less negative. (correct)
Why is the electron gain enthalpy of oxygen and fluorine less negative than that of the succeeding elements?
Why is the electron gain enthalpy of oxygen and fluorine less negative than that of the succeeding elements?
Which quantum level is more affected by electron-electron repulsion when adding an electron?
Which quantum level is more affected by electron-electron repulsion when adding an electron?
What is the IUPAC name for the element with atomic number 120?
What is the IUPAC name for the element with atomic number 120?
What does electronegativity refer to in a chemical compound?
What does electronegativity refer to in a chemical compound?
Which orbital begins to fill in the third period?
Which orbital begins to fill in the third period?
Which of the following scales is used to measure electronegativity?
Which of the following scales is used to measure electronegativity?
How does the effective nuclear charge affect the ease of adding an electron?
How does the effective nuclear charge affect the ease of adding an electron?
How many elements are there in the second period?
How many elements are there in the second period?
What is the electronic configuration of beryllium?
What is the electronic configuration of beryllium?
Which element's atomic number is represented by 'n = 2' in the second period?
Which element's atomic number is represented by 'n = 2' in the second period?
What do the roots 'un', 'bi', and 'nil' represent in naming elements?
What do the roots 'un', 'bi', and 'nil' represent in naming elements?
When does the filling of the 4s orbital begin?
When does the filling of the 4s orbital begin?
How many elements are in the third period?
How many elements are in the third period?
What does the valence of an element represent?
What does the valence of an element represent?
What is the valence of aluminium when it forms compounds?
What is the valence of aluminium when it forms compounds?
What is the oxidation state often used to describe?
What is the oxidation state often used to describe?
In the compound Na2O, what is the valence of sodium?
In the compound Na2O, what is the valence of sodium?
What is the formula for the oxide formed by aluminium?
What is the formula for the oxide formed by aluminium?
What periodic trend is associated with the valence of non-metals?
What periodic trend is associated with the valence of non-metals?
What is the valence of sulphur in compounds?
What is the valence of sulphur in compounds?
Which of the following compounds has a formula that reflects the valence of phosphorus?
Which of the following compounds has a formula that reflects the valence of phosphorus?
What is the oxidation state of aluminum in [AlCl(H2O)5]?
What is the oxidation state of aluminum in [AlCl(H2O)5]?
Which element is likely to form the most basic oxide?
Which element is likely to form the most basic oxide?
Which of the following oxides is considered acidic?
Which of the following oxides is considered acidic?
What is the covalency of aluminum in [AlCl(H2O)5] according to the content?
What is the covalency of aluminum in [AlCl(H2O)5] according to the content?
How does non-metallic character change across a period?
How does non-metallic character change across a period?
Which of the following statements about p-block elements is accurate?
Which of the following statements about p-block elements is accurate?
What type of oxides do elements in the center of a period typically form?
What type of oxides do elements in the center of a period typically form?
Which of the following reactions best illustrates the chemical reactivity of an element?
Which of the following reactions best illustrates the chemical reactivity of an element?
Which element is likely to be the least reactive based on its ionization enthalpy values?
Which element is likely to be the least reactive based on its ionization enthalpy values?
Which element is likely the most reactive metal?
Which element is likely the most reactive metal?
Which element is expected to be the most reactive non-metal based on its electron gain enthalpy?
Which element is expected to be the most reactive non-metal based on its electron gain enthalpy?
Which of the following elements would likely be categorized as the least reactive non-metal?
Which of the following elements would likely be categorized as the least reactive non-metal?
Which element is likely to form a stable binary halide of the formula MX2 where X is a halogen?
Which element is likely to form a stable binary halide of the formula MX2 where X is a halogen?
Which metal can predominantly form a stable covalent halide in the form of MX?
Which metal can predominantly form a stable covalent halide in the form of MX?
In the modern periodic table, what does the period number indicate?
In the modern periodic table, what does the period number indicate?
Which statement regarding the modern periodic table is incorrect?
Which statement regarding the modern periodic table is incorrect?
Study Notes
Periodic Trends and Chemical Reactivity
- The periodic table is a systematic way to organize the elements based on their properties
- Elements in the same group (column) share similar chemical properties
- As you go down a group, atomic radius increases due to the addition of electron shells
- As you move across a period (row), atomic radius decreases due to increasing nuclear charge
Ionization Enthalpy
- Ionization enthalpy is the energy required to remove an electron from a gaseous atom in its ground state
- It increases as you move across a period due to increased nuclear charge and smaller atomic radius
- It decreases as you move down a group due to increased atomic radius and less attraction between the nucleus and outermost electron
Electron Gain Enthalpy
- Electron gain enthalpy is the energy change when an electron is added to a gaseous atom in its ground state
- It generally becomes more negative moving across a period due to increased effective nuclear charge
- It generally becomes less negative moving down a group due to increased size of the atom and reduced attraction between the nucleus and incoming electron
- There are exceptions: oxygen and fluorine have less negative electron gain enthalpy than the succeeding elements due to electron-electron repulsion
Electronegativity
- Electronegativity is the ability of an atom in a compound to attract shared electrons to itself
- Electronegativity increases across a period due to increased nuclear charge and smaller atomic radius
- Electronegativity decreases down a group due to larger atomic radius and weaker attraction between the nucleus and electrons
Periodic Trends in Valence
- The valence of an element is the number of electrons used in bonding
- Valence is usually related to the number of electrons in the outermost shells
- The oxidation state is a more modern term for valence
Variable Valence
- Many elements exhibit variable valence depending on the nature of the compound they are in
Metallic and Non-Metallic Character
- Metallic character increases as you move down a group
- Metallic character decreases as you move across a period
- Non-metallic character increases as you move across a period
- Non-metallic character decreases as you move down a group
Reactivity of Elements with oxygen
- Elements on the extremes of a period readily react with oxygen
- Elements on the left side of the periodic table form basic oxides
- Elements on the right side of the periodic table form acidic oxides
- Elements in the middle tend to form amphoteric or neutral oxides
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Description
Test your understanding of periodic trends and chemical reactivity in this quiz. Explore concepts such as atomic radius, ionization enthalpy, and electron gain enthalpy. Challenge yourself to accurately answer questions based on the organization of elements in the periodic table.
