Periodic Properties of Elements

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Questions and Answers

What is the group known as alkali metals?

Group 2

Group 16

Group 17

Group 1 (correct)

Which of the following groups are classified as noble gases?

Group 14

Group 16

Group 1

Group 18 (correct)

What defines the metallic radius of an atom?

The total volume occupied by an atom

One-half the distance between nuclei of adjacent atoms (correct)

The distance from the nucleus to the outermost electron

One-half the distance between bonded atoms

What trend in atomic size occurs when the principal quantum number (n) increases?

Atomic size increases Signup and view all the answers

What do chalcogens represent in the periodic table?

Group 16 Signup and view all the answers

What is the term for the positive charge 'felt' by an electron?

Effective nuclear charge (Zeff) Signup and view all the answers

Where are the f-block elements positioned in relation to the main body of the periodic table?

At the bottom of the table Signup and view all the answers

What happens to outer electrons as the effective nuclear charge (Zeff) increases?

They are pulled closer to the nucleus Signup and view all the answers

Which group of elements generally does not have a tendency to gain electrons?

Noble gases Signup and view all the answers

What happens to electronegativity as you move across a period from left to right?

It increases. Signup and view all the answers

How does metallic character change as you move down a group?

It increases. Signup and view all the answers

What type of element is characterized by having small numbers of electrons in their outermost shell?

Metals Signup and view all the answers

What is the effect of increased atomic radius on electronegativity as you move down a group?

Electronegativity decreases. Signup and view all the answers

Which property describes a substance with all paired electrons under a magnetic field?

Diamagnetic Signup and view all the answers

What describes nonmetals in their behavior towards electrons?

They gain or share electrons. Signup and view all the answers

What is the effect of increasing the number of valence electrons on metallic property when moving across a period?

Metallic property decreases. Signup and view all the answers

Who is credited with the modern arrangement of the periodic table based on atomic number?

Henry Gwyn Jeffreys Moseley Signup and view all the answers

What did Dmitri Mendeleev predict about elements when he arranged them in his periodic table?

Properties of undiscovered elements Signup and view all the answers

In the periodic table, what is a 'group'?

A vertical column of elements Signup and view all the answers

What is the main focus of Julius Lothar Meyer’s work in organizing the periodic table?

Physical properties of elements Signup and view all the answers

What does the 'periodic law' refer to?

The predictable patterns in the physical properties of elements Signup and view all the answers

What aspect of the periodic table remains similar from Mendeleev’s original table to today’s version?

The grouping of elements with similar properties Signup and view all the answers

Which of the following statements about periods in the periodic table is correct?

All members of a period have the same highest principal quantum number Signup and view all the answers

Which chemist worked independently from Mendeleev and created a similar organization of elements?

Julius Lothar Meyer Signup and view all the answers

What is the general trend in atomic size as you move down a group in the periodic table?

Atomic size generally increases Signup and view all the answers

Which of the following elements is expected to have the highest first ionization energy?

Kr Signup and view all the answers

How does electron affinity generally change as you move down a group in the periodic table?

It becomes less negative Signup and view all the answers

Which element is most likely to form an anion based on its first ionization energy?

Te Signup and view all the answers

What is the relationship between atomic size and ionization energy?

As atomic size increases, ionization energy decreases Signup and view all the answers

Which group of elements typically has the most negative first electron affinities?

Group 17 elements Signup and view all the answers

Which of the following correctly ranks these elements by decreasing atomic size?

Sr, Ca, Rb Signup and view all the answers

What is true about the trend in second electron affinity compared to first electron affinity?

EA2 is always positive Signup and view all the answers

Study Notes

Development and Organization of the Periodic Table

Dmitri Mendeleev, a Russian chemist, created a periodic table arranging 65 elements by atomic mass, predicting properties of undiscovered elements.
Julius Lothar Meyer, a German chemist, independently arrived at a similar periodic organization focusing on physical properties.
Modern periodic table aligns elements by atomic number, a change credited to Henry Moseley, an English physicist.

Trends in the Periodic Table

The periodic law states that elements exhibit periodic recurrence of similar properties when arranged by atomic number.
Groups: Vertical columns in the periodic table with elements sharing similar properties, indicated by group numbers.
Periods: Horizontal rows where all elements share the same highest principal quantum number, numbered from left to right.

Main-Group Elements

S-block includes alkali metals (Group 1) and alkaline earth metals (Group 2).
P-block consists of chalcogens (Group 16), halogens (Group 17), and noble gases (Group 18).
D-block elements are known as transition metals; f-block elements, including lanthanides and actinides, are placed below the main table.

Trends in Atomic Size

Atomic size is defined by the distance between adjacent atomic nuclei, typically halved for measurement.
The metallic radius applies to metals; covalent radius is for nonmetals.
Atomic size increases down a group due to higher principal quantum numbers, while it decreases across a period due to increased effective nuclear charge.

Trends in Ionization Energy

Ionization energy (IE) is the energy needed to remove one mole of electrons from gaseous atoms or ions, generally positive due to the attraction between nucleus and electrons.
First ionization energy (IE1) removes the outermost electron; successive ionization energies (IE2, IE3, etc.) require more energy.
Ionization energies decrease with increasing atomic size.

Trends in Electron Affinity

Electron affinity (EA) measures energy change when adding an electron to an atom, typically negative for the first addition.
Group 17 elements tend to exhibit large negative electron affinities, while EA2 is always positive due to repulsion when adding a second electron.
Noble gases have minimal electron affinity as they require energy to enter the next shell.

Trends in Electronegativity

Electronegativity (EN) measures an atom's ability to attract electrons in a bond.
EN increases left to right across a period due to higher nuclear charge and decreases top to bottom in a group due to greater distance from the nucleus.

Trends in Metallic Character

Metals have few electrons in their outer shell, can easily lose electrons to form cations, exhibit conductivity, and are malleable.
Nonmetals tend to gain electrons, forming anions, and are generally poor conductors.
Metallic character decreases across a period and increases down a group, linked to atomic size and shell number.

Magnetic Properties

Magnetic behavior of atoms and ions is influenced by their electron configurations.
Diamagnetic substances have paired electrons, resulting in cancelled magnetic effects.

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Description

Explore the development and organization of the periodic table with insights into atomic structure and reactivity. This quiz covers key trends as identified by Dmitri Mendeleev and summarizes their behavior. Test your knowledge on how elements are organized and their recurring characteristics.