Question

low shows the elements comprising earth’s crust in percent by mass. pie chart: x, aluminum, iron, calcium, sodium, magnesium, potassium, other, oxygen the letter x represent? b) hydrogen c) nitrogen mostly b) gaseous air c) so tifies the interface between the lithosphere and the troposphere? diagram: outer space, sun, d, atmosphere, c (land), b (ocean), a b) line a c) line b science references tables, the element oxygen is found in the earth’s drosphere, only c) troposphere, only phere, and crust d) hydrosphere, only cience reference tables, the most abundant gas in the atmosphere b) oxygen c) nitrogen percentage of elements by volume.

Explanation:

To solve the problem of identifying what \( X \) represents in the pie chart of Earth’s crust elements (by mass), we use knowledge of Earth’s crust composition:

Step 1: Recall Earth’s Crust Elements

The Earth’s crust (by mass) has major elements: Oxygen (most abundant), Silicon, Aluminum, Iron, Calcium, etc. The pie chart shows Oxygen as the largest segment, and \( X \) is the second - largest.

Step 2: Eliminate Incorrect Options

• Hydrogen (Option B): Hydrogen is not a major element in Earth’s crust (it’s more abundant in the atmosphere/hydrosphere in other forms, but not in the crust’s mass - based composition).
• Nitrogen (Option C): Nitrogen is dominant in the atmosphere, not the crust.

• Silicon is the second - most abundant element in Earth’s crust by mass. Since the options given (from the visible part: B - Hydrogen, C - Nitrogen) are incorrect, and the correct element for \( X \) (based on crust composition) should be Silicon (even though not listed in the visible wrong options here, but from the context of crust elements, we analyze the options). Wait, maybe there was a typo or missing option, but from the given options (B: Hydrogen, C: Nitrogen), we know that Hydrogen and Nitrogen are not major crust elements. If we assume the correct option (even if not fully visible) - the major element after Oxygen in crust mass is Silicon. But from the given options, we can eliminate B and C.

Assuming the question has a missing option (like Silicon), but based on the analysis of the given wrong options (Hydrogen and Nitrogen are not crust - major), the correct element for \( X \) (second - most in crust mass) is Silicon (though not in the visible options here, but the process is as above).

For the other questions:

Question about Atmosphere’s Most Abundant Gas

The atmosphere is mostly nitrogen (about 78%) and oxygen (about 21%). So the most abundant gas in the atmosphere is nitrogen (Option C).

Question about Oxygen’s Presence

Oxygen is found in the hydrosphere (water: \( H_2O \)), atmosphere ( \( O_2 \), \( O_3 \) ), and crust (in minerals like silicates, oxides). So the correct option would be the one stating hydrosphere, atmosphere, and crust.

Final Answers (for each sub - question):

1. For “What does \( X \) represent?” (assuming the correct element is Silicon, and eliminating B and C): The answer depends on the full option list, but from given B (Hydrogen) and C (Nitrogen) are wrong.
2. For “Most abundant gas in atmosphere”: \(\boldsymbol{\text{C (nitrogen)}}\)
3. For “Oxygen’s presence”: The option stating hydrosphere, atmosphere, and crust (depending on the full option list, e.g., if an option is “hydrosphere, atmosphere, and crust”, that’s correct).

(Note: Some questions have incomplete option lists in the provided image, but the above is the analysis based on visible parts and Earth science knowledge.)

Answer:

To solve the problem of identifying what \( X \) represents in the pie chart of Earth’s crust elements (by mass), we use knowledge of Earth’s crust composition:

Step 1: Recall Earth’s Crust Elements

The Earth’s crust (by mass) has major elements: Oxygen (most abundant), Silicon, Aluminum, Iron, Calcium, etc. The pie chart shows Oxygen as the largest segment, and \( X \) is the second - largest.

Step 2: Eliminate Incorrect Options

• Hydrogen (Option B): Hydrogen is not a major element in Earth’s crust (it’s more abundant in the atmosphere/hydrosphere in other forms, but not in the crust’s mass - based composition).
• Nitrogen (Option C): Nitrogen is dominant in the atmosphere, not the crust.

• Silicon is the second - most abundant element in Earth’s crust by mass. Since the options given (from the visible part: B - Hydrogen, C - Nitrogen) are incorrect, and the correct element for \( X \) (based on crust composition) should be Silicon (even though not listed in the visible wrong options here, but from the context of crust elements, we analyze the options). Wait, maybe there was a typo or missing option, but from the given options (B: Hydrogen, C: Nitrogen), we know that Hydrogen and Nitrogen are not major crust elements. If we assume the correct option (even if not fully visible) - the major element after Oxygen in crust mass is Silicon. But from the given options, we can eliminate B and C.

Assuming the question has a missing option (like Silicon), but based on the analysis of the given wrong options (Hydrogen and Nitrogen are not crust - major), the correct element for \( X \) (second - most in crust mass) is Silicon (though not in the visible options here, but the process is as above).

For the other questions:

Question about Atmosphere’s Most Abundant Gas

The atmosphere is mostly nitrogen (about 78%) and oxygen (about 21%). So the most abundant gas in the atmosphere is nitrogen (Option C).

Question about Oxygen’s Presence

Oxygen is found in the hydrosphere (water: \( H_2O \)), atmosphere ( \( O_2 \), \( O_3 \) ), and crust (in minerals like silicates, oxides). So the correct option would be the one stating hydrosphere, atmosphere, and crust.

Final Answers (for each sub - question):

1. For “What does \( X \) represent?” (assuming the correct element is Silicon, and eliminating B and C): The answer depends on the full option list, but from given B (Hydrogen) and C (Nitrogen) are wrong.
2. For “Most abundant gas in atmosphere”: \(\boldsymbol{\text{C (nitrogen)}}\)
3. For “Oxygen’s presence”: The option stating hydrosphere, atmosphere, and crust (depending on the full option list, e.g., if an option is “hydrosphere, atmosphere, and crust”, that’s correct).

(Note: Some questions have incomplete option lists in the provided image, but the above is the analysis based on visible parts and Earth science knowledge.)