Question

(a) The five most abundant elements in the Earth's crust are \(\mathrm{O}, \mathrm{Si}, \mathrm{Al}, \mathrm{Fe},\) and Ca. Referring to Figure \(7.1,\) are any of these elements among those known before \(1700 ?\) If so which ones? (b) Seven of the nine elements known since ancient times are metals. Referring to Table \(4.5,\) are these metals mostly found at the bottom or top of the activity series?

Short answer

The five most abundant elements in the Earth's crust are Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), and Calcium (Ca). Out of these elements, only Iron (Fe) was known before 1700. The seven ancient metals are mostly found at the bottom of the activity series, according to the activity series in Table 4.5.

Step-by-step solution

Check the most abundant elements in the Earth's crust

Referring to Figure 7.1, the five most abundant elements in the Earth's crust are Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), and Calcium (Ca).

Determine which of these elements were known before 1700

According to the historical context, the elements known since ancient times before 1700 are: Gold (Au), Copper (Cu), Silver (Ag), Tin (Sn), Lead (Pb), Mercury (Hg), and Iron (Fe). From the list above, only **Iron (Fe)** is among the Earth's five most abundant elements. #b. Metals Position in the Activity Series#

Identify the activity series of metals

Referring to Table 4.5, the activity series of metals is a list showing metals in order of decreasing reactivity based on their ability to displace hydrogen from water and acids.

Compare the ancient metals to the activity series

The seven ancient metals are Gold (Au), Copper (Cu), Silver (Ag), Tin (Sn), Lead (Pb), Mercury (Hg), and Iron (Fe). We need to check their position in the activity series, which is: - K, Na, Ca, Mg, Al, Zn, **Fe**, Sn, **Pb**, H, **Cu**, **Ag**, **Hg**, **Au** (From top to bottom) Out of the seven ancient metals, six of them are found in the bottom half of the activity series: Gold (Au), Copper (Cu), Silver (Ag), Tin (Sn), Lead (Pb), and Mercury (Hg). Only Iron (Fe) is found in the top half. Conclusion: The ancient metals are mostly found at the **bottom** of the activity series.

Key concepts

Ancient Elements Known before 1700

Before the year 1700, humanity had already discovered a handful of elements. These are often called the ancient elements, as they were recognized and utilized in their elemental forms by ancient civilizations. Commonly known ancient elements include Gold (Au), Copper (Cu), Silver (Ag), Tin (Sn), Lead (Pb), Mercury (Hg), and Iron (Fe).
This discovery timeline is critical as it provides insight into historical metallurgy and early chemistry. Among these, only Iron (Fe) is one of the five most abundant elements in Earth's crust. Being one of the earliest known elements, Iron significantly impacted technology through its use in tools and structures.
The knowledge of these ancient elements laid the foundation for the modern study of chemistry.

Activity Series of Metals

The activity series of metals is a ranking of metals based on their reactivity. It is especially useful to determine how metals react with acids and water, showing which metals are more likely to displace other elements. In simple terms, this series helps predict the chemical behavior of each metal during reactions.
Metals are typically listed in the activity series from most reactive to least reactive. In the series, metals like Potassium (K) and Sodium (Na) are extremely reactive. Interestingly, a number of the ancient metals, such as Gold (Au), Copper (Cu), Silver (Ag), and Mercury (Hg), are found near the bottom of the series. This indicates they do not readily participate in chemical reactions.

• More reactive metals can displace less reactive metals from a compound.
• The position along the series implies a metal's tendency to oxidize (lose electrons).

Historical Context of Elements

Studying the historical context of elements enhances our understanding of early scientific progress. The elements known before 1700 highlight the materials that were significant to early human society. Many of these were discovered as native metals and were used by ancient cultures for conducting electricity, minting currency, or crafting tools.
The knowledge of these elements was limited by the technology of the time. Science has since advanced, broadening our ability to discover new elements and comprehend their properties. However, the historical significance remains, providing a glimpse into the ingenuity and adaptability of ancient societies.
For instance, the use of Copper is well-documented in tools and decoration since the Bronze Age. This underlines how these early discoveries have shaped both the technological and cultural advances throughout history.