Question

name:__ date:__ nitrogen 78% carbon dioxide 0.04% argon 0.9% all other gases 0.06% oxygen 21% comprehension & observation 1. which gas makes up the largest part of earth’s atmosphere? 2. what gas do humans need most for breathing? how much of it is in the atmosphere? 3. which gas takes up the smallest portion in the chart? critical thinking 4. why do you think carbon dioxide gets so much attention, even though it’s less than 1% of the atmosphere? 5. why is nitrogen so abundant if we don’t breathe it in the same way as oxygen? 6. if oxygen increased to 30%, what might be the risks or benefits? real - world connection 7. how do human activities like burning fossil fuels affect the composition of the atmosphere? 8. what role do trace gases (like water vapor and ozone) play in earth’s climate or weather?

Explanation:

1. By observing the pie - chart percentages, nitrogen has the highest proportion at 78%, so it makes up the largest part of Earth's atmosphere.
2. Humans need oxygen most for breathing. According to the chart, it is 21% of the atmosphere.
3. Carbon dioxide has the smallest percentage at 0.04% among the listed gases.
4. Carbon dioxide is a greenhouse gas. Even in small amounts, it can trap heat in the Earth's atmosphere, leading to global warming and climate change, which is why it gets a lot of attention.
5. Nitrogen is abundant because it is released from the Earth's crust during geological processes and is also recycled through the nitrogen cycle in nature. It is not used up in the same way as oxygen in respiration for most organisms.
6. Benefits: Higher oxygen levels could improve physical performance and endurance. Risks: Increased fire hazards as oxygen supports combustion, and potential for oxygen toxicity over time.
7. Burning fossil fuels releases carbon dioxide, increasing its concentration in the atmosphere and contributing to the greenhouse effect and climate change.
8. Water vapor is a powerful greenhouse gas and affects humidity and precipitation. Ozone in the stratosphere protects life on Earth by absorbing harmful ultraviolet radiation, while ground - level ozone can be a pollutant and harmful to human health and plants.

Answer:

1. Nitrogen
2. Oxygen, 21%
3. Carbon dioxide
4. It is a greenhouse gas causing climate change.
5. Due to geological processes and the nitrogen cycle.
6. Benefits: Improved physical performance. Risks: Higher fire risk, oxygen toxicity.
7. Releases carbon dioxide, increasing its concentration.
8. Water vapor affects humidity and precipitation; stratospheric ozone protects from UV, ground - level ozone is a pollutant.