What Are P-Block Elements?
The p-block is on the right side of the periodic table and includes elements from the six columns beginning with column 3A and ending with column 8A (or columns 13-18 on some versions of the periodic table). Helium, which is in the top of column 8A, is not included in the p-block. In the periodic table shown here, the p-block is colored orange.
P-block elements are unified by the fact that their valence electrons (outermost electrons) are in the p orbital. The p orbital consists of six lobed shapes coming off a central point at evenly spaced angles. The p orbital can hold a maximum of six electrons, hence why there are six columns in the p-block. Elements in column 3A, the first column of the p-block, have one valence electron. Elements in column 4A, the second column of the p-block, have two valence electrons. The trend continues this way until we reach column 8A, which has six valence electrons.
There are 35 elements that live in the p-block, which can be seen here.
The p-block is home to the biggest variety of elements and is the only block that contains all three types of elements: metals, nonmetals, and metalloids. Generally, the p-block elements are best described in terms of element type or column number.
Properties of P-Block Metals
P-block metals have classic metal characteristics: they are shiny, they are good conductors of heat and electricity, and they lose electrons easily. Generally, these metals have high melting points and readily react with nonmetals to form ionic compounds. Ionic compounds form when a positive metal ion bonds with a negative nonmetal ion.
Of the p-block metals, several have fascinating properties. Gallium, in the 3rd row of column 3A, is a metal that can melt in the palm of your hand. Tin, in the fourth row of column 4A, is an abundant, flexible, and extremely useful metal. It is an important component of many metal alloys like bronze, solder, and pewter.
Sitting right beneath tin is lead, a toxic metal with an intriguing history. Ancient peoples used lead for a variety of things, from food sweeteners to pottery glazes to eating utensils. Unbeknownst to these ancient civilizations, lead is quite toxic. Many historians suspect that lead poisoning is related to the fall of Roman civilization. For a long time, lead was used in the manufacturing of paints. It was only within the last century that lead paint use has been restricted due to its toxic nature.
Properties of P-Block Metalloids
Metalloids have properties of both metals and nonmetals, but the term 'metalloid' lacks a strict definition. All of the elements that are commonly recognized as metalloids are in the p-block: boron, silicon, germanium, arsenic, antinomy, and tellurium.
Silicon is perhaps the most famous metalloid. It is the second most abundant element in Earth's crust and one of the main ingredients in glass. It is used to make microchips for computers and other electronic devices. So valuable is silicon to the technology industry that Silicon Valley in California is named after it.
Germanium has properties very similar to silicon, yet this element is much more rare. Arsenic is a toxic metalloid that has been used throughout history as an additive to metal alloys, paints, and even makeup.
Properties of P-Block Nonmetals
Most of the p-block elements are nonmetals. These elements generally have low boiling points, are poor conductors, and do not lose electrons easily. Some nonmetals are solids at room temperature, while others are gases. One nonmetal in the p-block, bromine, is a liquid at room temperature.
Carbon, phosphorus, sulfur, selenium, and iodine regularly occur as solids. Pure carbon commonly occurs as graphite or diamond, but it can bond with other elements to form a variety of compounds. Carbon is considered to be the most important element to life because most compounds essential to living things contain carbon. Phosphorus, sulfur, selenium, and iodine make brittle solids of various colors.
Nitrogen and oxygen often occur as gases, and both elements are important to living organisms. Nitrogen is the most abundant element in our atmosphere; approximately 78% of it is made of nitrogen. In its gaseous form, oxygen makes up 20% of our atmosphere.
Halogens and Noble Gases
Column 7A is made of five nonmetal elements with very similar properties. Collectively, these p-block elements are known as the halogens. They have five electrons in their p orbital and are known for being extremely greedy for electrons. They like to steal electrons from metal elements to become 1- ions. If stealing electrons is not a possibility, they will bond with themselves and share electrons. Fluorine, chlorine, and bromine gases are toxic, while astatine is so radioactive it decays almost as soon as it exists.
The group that resides in column 8A is called the noble gases. Their p orbitals contain six electrons. This group is nonreactive and generally does not bond with other elements, preferring to exist by themselves. These gases are clear and odorless.
Now let's talk about some new discoveries. Elements 113-118 may have either just been discovered or they very likely exist. These elements have all been created in laboratories using particle accelerators. For the most part, they are such unstable elements that they only exist for a few seconds (or even less time) before they decay. It is assumed that their properties would be similar to other p-block elements.
The p-block is the area of the periodic table containing columns 3A to column 8A (columns 13-18), not including helium. There are 35 p-block elements, all of which have valence electrons in the p orbital.
The p-block elements are a very diverse group of elements with a wide range of properties. The p-block contains metal, nonmetal, and metalloid elements. Some of these elements are extremely abundant (oxygen, silicon), some are toxic (lead, arsenic), and some are very useful (tin, aluminum).
It is also home to the very reactive halogens (column 7A), the nonreactive noble gases (column 8A), and some of the most recently discovered elements (elements 113-118).
P-Block Study Guide & Chart
P-block - the portion on the right side of the periodic table which includes elements from the six columns beginning with column 3A and ending with column 8A (or columns 13-18 on some versions of the periodic table); excludes helium
Ionic compounds - compounds which form when a positive metal ion bonds with a negative nonmetal ion
|Characteristics||High melting points, react to form ionic compounds||Low boiling points, poor conductors, don't lose electrons easily||Properties of both metals and non-metals||Steal electrons from metals to become 1- ions; also bond with themselves||P orbitals contain six electrons; nonreactive, clear and odorless|
|P-Block Examples||Gallium (3A), Tin (4A), Lead (4A)||Carbon (4A), Phosphorus (5A), Oxygen (6A)||Silicon (6A), Germanium (4A), Arsenic (5A)||Column 7A||Column 8A (except helium)|
Study the lesson until you feel prepared to:
- Locate the p-block on the periodic table
- Explain what unifies p-block elements
- Identify the properties of metals, metalloids, nonmetals, halogens, and noble gases
- List examples of each type of element from the p-block
- Discuss elements 113-118
To unlock this lesson you must be a Study.com Member.
Create your account
Discussion Questions on p-Block Elements
The following questions are meant for discussion and exploration.
The Diamond Structure
Pure carbon has a couple of allotropes. One is graphite and one is diamond, the hardest natural mineral. A picture of how carbons are bonded in diamond is below:
- A couple of other elements crystallize in the diamond structure - which ones would you expect to do this based on bonding in diamond?
- Diamond is a covalent network solid, but its relatives having diamond structure are not very covalent. Why?
Chemical Properties of Oxygen and Sulfur
- Elemental oxygen exists as O2, but elemental sulfur exists primarily as S8. Can this be explained based on their positions on the periodic table?
- Lewis dots predict elemental oxygen to have a double bond, but it actually exists as a biradical. What does this implicate about its reactivity?
Row 2 Elements
- C, O and N are by far the most abundant elements in living organisms. What is so special about row 2?
The Diamond Structure:
- Silicon and germanium are the other elements that crystallize in the diamond structure.
- Carbon is small, so p orbitals on interacting atoms overlap very well. Silicon and especially germanium are bigger and their orbitals have less overlap, so while there is covalent character in silicon bonds, it is not very strong. Germanium is considered barely or non-covalent.
Chemical Properties of Oxygen and Sulfur:
- Again it's about orbital size. The larger sulfur atom prefers to make single bonds and S(2) is possible, so more atoms have larger Van der Waals forces. Sulfur's size makes an 8-membered ring favorable.
- As a biradical, oxygen is far more reactive than it would be if it were double-bonded.
Row 2 Elements:
- Again, size. Row 2 atoms are small and they all have p orbitals that are the same size, so they form relatively short and strong sigma and pi bonds with one another. This allows for organic and biomolecules to be especially resilient.
Register to view this lesson
Unlock Your Education
See for yourself why 30 million people use Study.com
Become a Study.com member and start learning now.Become a Member
Already a member? Log InBack