ATOM AND PERIODIC TABLE II

What percentage of oxygen in the blood is typically bound to hemoglobin?

98.5% of oxygen ($\text{O}_2$) is bound to a protein called hemoglobin¹. Only about 1.5% dissolves directly in the blood².

What element in hemoglobin is responsible for binding oxygen and giving blood its red color?

Iron ($\text{Fe}^{2+}$) associated with the heme groups in hemoglobin binds to oxygen ($\text{O}_2$) and gives blood its characteristic red color³.

Why is the Periodic Table necessary?

The Periodic Table is needed to organize and classify the more than 100 elements based on their chemical and physical properties

Which features of an element can be deduced from its position on the Periodic Table?

You can deduce its electronic configuration if you know ⁵: Number of valence electrons (similar within a group) ⁶. Period number (corresponds to the principal quantum number of the valence shell, $n$) ⁷. * Group number (corresponds to the number of valence electrons)

How is the Periodic Table divided into four major blocks?

It's divided into four blocks (s, p, d, f) based on the type of orbital that the outermost electron (valence electron) is filling.

s-block

Elements where the outermost electron fills the s-orbitals ($\text{ns}^1$ for Group 1 - alkali metals; $\text{ns}^2$ for Group 2 - alkaline earth metals)¹⁰.

p-block

Elements where the outermost electron fills the p-orbitals ($\text{ns}^2\text{np}^{1}$ to $\text{ns}^2\text{np}^{6}$). This includes Group 13 to Group 18¹¹.

d-block

Elements where the outermost electron fills the d-orbitals ($d^1$ to $d^{10}$). These are the Transition elements (Groups 3–12)¹².

f-block

Elements where the outermost electron fills the f-orbitals (4f and 5f). These are the Inner transition elements (Lanthanides in Period 6 and Actinides in Period 7)

Group 18

Known as Noble Gases. They have 8 valence electrons, are inert (not reactive), and exist naturally as they "refuse to play with anyone".

What are the general characteristics of a metal?

Metals are typically malleable (can be pounded into shapes), have a lustrous appearance, are good conductors of heat and electricity, and are generally solid at room temperature (except mercury).

Describe the properties of metalloids and where they are located.

Metalloids are located in a zigzag band between metals and nonmetals. Their properties are intermediate between those of a metal and nonmetal, such as pure silicon having a lustrous surface like a metal but being brittle like a nonmetal

What trend in metallic/non-metallic character is observed as you move from left to right across a period?

The elements generally change from metallic to non-metallic in character across a period (from left to right)