Question

Arrange the following groups of atoms in order of increasing size. a. Te, S, Se b. K, Br, Ni c. Ba, Si, F

Short answer

The order of increasing atomic size for the given groups of atoms is: a. S < Se < Te b. Ni < Br < K c. F < Si < Ba

Step-by-step solution

Identify the elements' positions in the periodic table

Te (Tellurium) is in the Group 16 (Chalcogens) and Period 5. S (Sulfur) is in Group 16 (Chalcogens) and Period 3. Se (Selenium) is in Group 16 (Chalcogens) and Period 4.

Determine the trend in atomic size

Since all elements are in the same group (Group 16), we expect the atomic size to increase with increasing period number. Thus, the order of increasing atomic size for these elements is: S < Se < Te #b. K, Br, Ni# We will follow these steps to find the order of increasing atomic size: 1. Identify the elements' positions in the periodic table. 2. Determine the trend in atomic size.

Identify the elements' positions in the periodic table

K (Potassium) is in Group 1 (Alkali Metals) and Period 4. Br (Bromine) is in Group 17 (Halogens) and Period 4. Ni (Nickel) is in Group 10 (Transition Metals) and Period 4.

Determine the trend in atomic size

Since all elements are in the same period (Period 4), we expect the atomic size to decrease as we move left to right across the periodic table. Thus, the order of increasing atomic size for these elements is: Ni < Br < K #c. Ba, Si, F# We will follow these steps to find the order of increasing atomic size: 1. Identify the elements' positions in the periodic table. 2. Determine the trend in atomic size.

Identify the elements' positions in the periodic table

Ba (Barium) is in Group 2 (Alkaline Earth Metals) and Period 6. Si (Silicon) is in Group 14 (Carbon Group) and Period 3. F (Fluorine) is in Group 17 (Halogens) and Period 2.

Determine the trend in atomic size

The elements are in different groups and periods. To address this, we can use their period numbers and use the trend of increasing atomic size down a group. Thus, the order of increasing atomic size for these elements is: F < Si < Ba

Key concepts

Periodic Table

The periodic table is a systematic way to organize all known elements based on their atomic number, which is the number of protons in an atom's nucleus. This beautiful arrangement reveals trends and patterns in the properties of the elements. The table is divided into rows called periods and columns known as groups or families. As you progress from left to right across a period, the atomic numbers of the elements increase, but atomic size tends to decrease. This trend is due to the increasing positive charge from the protons, pulling electrons closer to the nucleus.

• Elements in the same group generally share similar chemical properties because they have the same number of electrons in their outer shell.
• Moving down a group, elements typically increase in atomic size because each successive element has an additional electron shell.

Understanding the layout and trends of the periodic table helps predict an element's properties, such as its size, reactivity, and more.

Atomic Size

Atomic size or atomic radius refers to the distance from an atom's nucleus to the outermost shell containing electrons. It’s a crucial concept to comprehend because it affects physical and chemical properties.

• As you move down a group in the periodic table, atomic size increases. This is because there is an addition of electron shells, which makes the atoms larger.
• Conversely, as you move across a period from left to right, atomic size decreases. The increased number of protons exerts a greater pull on the electrons, drawing them closer to the nucleus.

An element's position in the periodic table is key to estimating its atomic size. For instance, because Potassium (K) is on the leftmost side of the periodic table, it is larger than Bromine (Br), and Nickel (Ni) which are placed further to the right, despite being in the same period.

Elements

Elements are pure substances consisting only of atoms that all have the same number of protons. Each element has unique properties, and they are the building blocks of matter. In the periodic table:

• Group 16 elements, like Sulfur (S), Selenium (Se), and Tellurium (Te) typically share properties due to having the same number of valence electrons.
• Period 4 elements such as Nickel (Ni), Bromine (Br), and Potassium (K) display varying atomic sizes due to their position across the table.
• Groups, such as Alkaline Earth Metals where Barium (Ba) resides, indicate similar reactivity among elements.

Different elements exhibit diverse chemical behaviors, making them fundamental to life and technology. Recognizing these attributes helps to predict reactions and understand the natural world. For scholars, understanding the elemental grouping in the periodic table is crucial for mastering chemistry basics.