Question

1) The percentage of oxygen in dry air is _______

A. 0.1
B. 1.0
C. 21
D. 79

2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?

A. Oxygen
B. Carbon dioxide
C. Ammonia
D. Nitrogen

Answer 1

Answer:

1) The percentage of oxygen in dry air is _______

C. 21

2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?

B. CARBON DIOXIDE

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Answer 2

Answer: The percentage of oxygen in dry air is .  21

Explanation:  Ammonia gases was present in large amounts  in the easth7s earliest atmosphere

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