Give the symbol of the element that has the (4.7) a. largest atomic size in Group 1A (1)

Verified step by step guidance

1. Step 1: Identify the elements in Group 1A (1) of the periodic table. These are the alkali metals, which include: Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
2. Step 2: Understand that atomic size increases as you move down a group in the periodic table. This is because each successive element has an additional electron shell, which increases the distance between the outermost electrons and the nucleus.
3. Step 3: Determine which element is at the bottom of Group 1A (1). This element will have the largest atomic size due to having the most electron shells.
4. Step 4: Recall that Francium (Fr) is the element at the bottom of Group 1A (1).
5. Step 5: Conclude that Francium (Fr) has the largest atomic size in Group 1A (1).

Key Concepts

Atomic Size

Atomic size refers to the distance from the nucleus of an atom to the outermost shell of electrons. It is influenced by the number of electron shells and the effective nuclear charge. In general, atomic size increases down a group in the periodic table due to the addition of electron shells.

Group 1A Elements

Group 1A, also known as the alkali metals, includes elements like lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). These elements have one electron in their outermost shell, which they readily lose to form positive ions, making them highly reactive and characterized by increasing atomic size down the group.

Periodic Trends

Periodic trends are patterns observed in the periodic table that describe how certain properties of elements change across periods and down groups. For atomic size, the trend shows that atomic radii increase as you move down a group due to the addition of electron shells, while they generally decrease across a period due to increased nuclear charge pulling electrons closer to the nucleus.