객관식
Which type of compound is composed only of metal atoms?
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1. Intro to General Chemistry
Chemical Properties
객관식
Which of the following best represents the approximate percentage of oxygen by volume in Earth's atmosphere?
A
50%
B
10%
C
21%
D
78%
검증된 단계별 안내1
Understand that Earth's atmosphere is primarily composed of nitrogen, oxygen, and other gases, with oxygen making up a significant but not majority portion by volume.
Recall or research the typical composition of dry air by volume, which is approximately 78% nitrogen, 21% oxygen, and 1% other gases such as argon and carbon dioxide.
Recognize that the percentage of oxygen by volume is about 21%, which is less than half but more than 10%, making it a distinct and well-known value.
Compare the given options (50%, 10%, 21%, 78%) to the known atmospheric composition and identify that 21% best matches the approximate oxygen content.
Conclude that the approximate percentage of oxygen by volume in Earth's atmosphere is 21%, based on standard atmospheric composition data.
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