Question

To what group number does each element belong? (a) oxygen (b) aluminum (c) silicon (d) tin (e) phosphorus

Short answer

Oxygen belongs to Group 16, aluminum to Group 13, silicon and tin to Group 14, and phosphorus to Group 15.

Step-by-step solution

Determining the Group of Oxygen

Referring to the periodic table, locate oxygen, which has the atomic number 8. Oxygen is in Group 16.

Determining the Group of Aluminum

Referring to the periodic table, locate aluminum, which has the atomic number 13. Aluminum is in Group 13.

Determining the Group of Silicon

Referring to the periodic table, locate silicon, which has the atomic number 14. Silicon is in Group 14.

Determining the Group of Tin

Referring to the periodic table, locate tin, which has the atomic number 50. Tin is in Group 14.

Determining the Group of Phosphorus

Referring to the periodic table, locate phosphorus, which has the atomic number 15. Phosphorus is in Group 15.

Key concepts

Atomic Number

The atomic number is one of the most fundamental properties of an element. It refers to the number of protons present in the nucleus of an atom. Because each element has a unique number of protons, the atomic number also serves as a unique identifier for each chemical element on the periodic table. For example, oxygen has an atomic number of 8, which means all oxygen atoms have 8 protons in their nucleus.

Understanding the atomic number is crucial because it not only tells us about the element's identity, but also implies the number of electrons in a neutral atom, which in turn influences the atom's chemical behavior and its placement on the periodic table. The elements in a periodic table are arranged in ascending order of atomic number, which highlights the importance of atomic number in the study of chemistry.

Chemical Elements

Chemical elements are pure substances that consist entirely of one type of atom, each characterized by its atomic number. They are the basic building blocks of matter and make up everything in the universe. There are 118 confirmed elements, each with unique properties that classify them into different categories on the periodic table, such as metals, nonmetals, and metalloids.

For instance, aluminum is a metal known for its light weight and high strength, reflected in its use in industries like aerospace. Each element's characteristics are determined by the structure of its atoms, including the number of protons, neutrons, and electrons. Elements can combine in various ways to form compounds, which have different properties from the elements they are made from, demonstrating the diversity of chemical elements.

Periodic Table Trends

The periodic table is not just a list of elements, but a matrix of information, showing patterns in the properties of elements. These patterns are known as periodic trends, and they are crucial for predicting an element's behavior in chemical reactions. Some of these trends include atomic radius, ionization energy, electronegativity, and metallicity.

For example, atomic radii decrease from left to right across a period due to the increasing positive charge in the nucleus, pulling electrons closer. On the contrary, ionization energy, which is the energy required to remove an electron, generally increases across a period for the same reason. Understanding these trends helps scientists and students alike to make educated guesses about how an element might interact with others, its reactivity, and even its role in biological systems.