Problem 103 - Chemistry and Chemical Reactivity

Question

Reviewing the periodic table. (a) Name the element in Group \(2 \mathrm{A}\) and the fifth period. (b) Name the element in the fifth period and Group \(4 B\). (c) Which element is in the second period in Group \(4 \mathrm{A} ?\) (d) Which element is in the fourth period in Group \(5 \mathrm{A} ?\) (e) Which halogen is in the fifth period? (f) Which alkaline earth element is in the third period? (g) Which noble gas element is in the fourth period? (h) Name the nonmetal in Group \(6 \mathrm{A}\) and the third period. (i) Name a metalloid in the fourth period.

Step-by-Step Solution

Answer

(a) Strontium, (b) Zirconium, (c) Carbon, (d) Arsenic, (e) Iodine, (f) Magnesium, (g) Krypton, (h) Sulfur, (i) Germanium.

Step 1: Identify Group and Period

To solve this exercise, first, identify the Groups (vertical columns) and Periods (horizontal rows) on the periodic table. Groups are often referred to as families and share similar chemical properties. Periods indicate the number of electron shells.

Step 2: Find the Element in Group 2A, Period 5

Look for the element located in Group 2A (alkaline earth metals) and Period 5. This element is Strontium (Sr).

Step 3: Find the Element in Group 4B, Period 5

Identify the element located in Group 4B and Period 5, which is Zirconium (Zr).

Step 4: Find the Element in Group 4A, Period 2

In Period 2 and Group 4A (Group 14), locate Carbon (C).

Step 5: Find the Element in Group 5A, Period 4

In Period 4 and Group 5A (Group 15), the element is Arsenic (As).

Step 6: Identify the Halogen in Period 5

The halogen in Period 5 is Iodine (I).

Step 7: Identify the Alkaline Earth Metal in Period 3

For the third period in Group 2A, the element is Magnesium (Mg).

Step 8: Identify the Noble Gas in Period 4

The noble gas in Period 4 is Krypton (Kr).

Step 9: Find the Nonmetal in Group 6A, Period 3

The nonmetal in Group 6A (Group 16) and Period 3 is Sulfur (S).

Step 10: Identify the Metalloid in Period 4

In Period 4, the metalloid is Germanium (Ge).

Key Concepts

Alkaline Earth Metals

Alkaline Earth Metals are an important group of elements in the periodic table. They are located in Group 2A. This group includes six elements: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).
These elements are known for being shiny, silvery-white, and somewhat reactive metals. Alkaline Earth Metals have two electrons in their outer shell, which explains their similar chemical properties.

• They react with water to form alkaline hydroxides, although not as vigorously as the alkali metals.
• These metals are usually found in various mineral compounds rather than in their free state.

One notable member from this group in the periodic table is Magnesium, a key component in the Earth's crust and essential to biological systems. This element plays a vital role in plant photosynthesis and is used in various industrial and medical applications.

Halogens

Halogens are located in Group 17 (7A) of the periodic table. This group consists of five elements: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At).
These elements are very reactive and are almost never found in their elemental form in nature. The term 'halogen' means 'salt-former', and compounds containing halogens are called 'salts'.

• Halogens have seven electrons in their outer shell, which makes them eager to gain one more electron to form stable negative ions.
• These elements can form compounds with all other elements, contributing to a wide range of chemical reactions.

Iodine, a halogen in the fifth period, is particularly important in human nutrition. It is a critical element for thyroid function, which regulates metabolism. In the periodic table, halogens are positioned on the right side, just before the noble gases.

Noble Gases

Noble gases make up Group 18 (8A) of the periodic table and include elements such as Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).
These elements are known for their lack of reactivity due to their full electron shells. Typically, they don't form compounds easily and are found as monatomic gases.

• Noble gases have a complete outer shell of electrons, giving them stability and making them inert.
• They are colorless, odorless, and tasteless, making them hard to detect without specialized instruments.

Krypton, the noble gas in the fourth period, is used in lighting and photographic flashes. Noble gases' stable-filled electron configurations make them useful as a themal insulator and in neon lights.

Metalloids

Metalloids are elements with properties that are intermediate between metals and nonmetals. They are located on the periodic table between metals and nonmetals, typically along the "stair-step" line. The commonly recognized metalloids include Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), and Tellurium (Te).
These elements have significant industrial applications due to their unique properties.

• Metalloids can conduct electricity, but not as well as metals, which makes them good semiconductor materials.
• They can form alloys and also display varying metallic and nonmetallic properties.

Germanium, a metalloid in the fourth period, is particularly important in electronics because of its semiconductor properties. Found in the middle region of the periodic table, metalloids bridge the gap between the distinctive properties of metals and nonmetals.