Question

Use the periodic table to identify the group numbers and period numbers of the following elements: a. carbon, C b. argon, Ar c. chromium, Cr d. barium, Ba

Short answer

Carbon: Group 14, Period 2. Argon: Group 18, Period 3. Chromium: Group 6, Period 4. Barium: Group 2, Period 6.

Step-by-step solution

Identify Carbon (C)

Locate carbon on the periodic table. Carbon is in Group 14 and Period 2.

Identify Argon (Ar)

Locate argon on the periodic table. Argon is in Group 18 and Period 3.

Identify Chromium (Cr)

Locate chromium on the periodic table. Chromium is in Group 6 and Period 4.

Identify Barium (Ba)

Locate barium on the periodic table. Barium is in Group 2 and Period 6.

Key concepts

group numbers

Group numbers are an essential aspect of the periodic table. They indicate the column in which an element is located. Each group often has elements with similar chemical properties because they possess the same number of electrons in their outermost shell.
For instance, elements in Group 1 (like hydrogen and sodium) are highly reactive metals.
To find the group number of an element, simply look at the top of the periodic table column above the element.
In our example, Carbon (C) is in Group 14, Argon (Ar) is in Group 18, Chromium (Cr) is in Group 6, and Barium (Ba) is in Group 2.
Knowing the group number helps predict how an element will behave in chemical reactions.

period numbers

Period numbers indicate the row in which an element is found on the periodic table. They represent the number of electron shells an atom has.
For example, elements in Period 2 have two electron shells, while elements in Period 4 have four electron shells.
Period numbers are crucial because they help us understand the structure of an atom and its electron configuration.
In the given exercise, Carbon (C) is in Period 2, Argon (Ar) is in Period 3, Chromium (Cr) is in Period 4, and Barium (Ba) is in Period 6.
This information is helpful when determining how elements interact and bond with each other.

element identification

Element identification involves locating an element on the periodic table using its atomic number and symbol. The atomic number represents the number of protons in an atom's nucleus.
Each element has a unique atomic number and symbol, making it easy to identify.
For example, Carbon has the symbol 'C' and atomic number 6, while Argon has the symbol 'Ar' and atomic number 18.
To identify elements like Chromium (Cr) and Barium (Ba), locate their symbols on the periodic table and find their group and period numbers.
This process is important for understanding the properties and behavior of specific elements in chemistry.

chemical elements

Chemical elements are the basic building blocks of matter. Each element is composed of atoms with the same number of protons.
There are 118 known elements, each with unique properties and characteristics.
Elements are organized on the periodic table based on their atomic structure and properties, facilitating easier study and understanding.
Examples of common elements include Carbon (C), essential in organic chemistry, Argon (Ar), a noble gas, Chromium (Cr), a transition metal, and Barium (Ba), an alkaline earth metal.
Understanding chemical elements is fundamental to studying and exploring the material world.