All categories

3 years ago

What was the oxygen crisis

1 answer:

8 0

The Great Oxidation Event (GOE), sometimes also called the Great Oxygenation Event, Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust,[2] or Oxygen Revolution, was a time period when the Earth's atmosphere and the shallow ocean first experienced a rise in oxygen, approximately 2.4 billion years ago (2.4 Ga) to 2.1–2.0 Ga during the Paleoproterozoic era.[3] Geological, isotopic, and chemical evidence suggests that biologically produced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere,[4] causing many existing species on Earth to die out.[5] The cyanobacteria producing the oxygen caused the event which enabled the subsequent development of multicellular forms.

You might be interested in

Base your answer on the information below. The radioisotope uranium-238 occurs naturally in Earth's crust. The disintegration of

algol [13]

Answer:

12 mmilligrams of Po-218 was the mass of the original starting material

Explanation:

The half-life of a radioactive material is the time taken for half the amount ofnthe original material present in a radioactive material to decay or disintegrate.

After each half-life, half the original material present at the start remains.

For the radioactive polonium-218 having a half-life of 3.04 minutes, it means that if 1 g is the starting material, after 3.04 minutes, 1/2 g will be remaining; after, 6.08 minutes 1/2 of 1/2 which is 1/4 of the starting material will be remaining; and after 9.12 minutes, 1/2 of 1/4 = 1/8 g will be remaining.

From the question, number of half-lives undergone after 9.12 minutes = 9.12/3.04 = 3 half-lives.

After 3 half-lives, 1/8 of the original material is remaining.

1/8 = 1.50 mg

The original mass of the sample at the start = 1.50 mg × 8 = 12 mg

Therefore, 12 milligrams of Po-218 was the mass of the original starting material.

4 0

3 years ago

How many Signifact figures does 0.000300

Deffense [45]

Answer:

3 significant digits

Explanation:

The first 0 don't count (that's the rule in significant digits). So 3,0,0 are left over. Count them and total will be 3 significant digits. (remember the last zero count if there is a decimal but the first zeros doesn't count even with the decimals)

6 0

3 years ago

What is the percentage of carbon in 5.00 g of sucrose

Irina-Kira [14]

The answer is rounded off to 0.0278 mol C6H12O6

3 0

3 years ago

What are some other economic or social disadvantages that you can think of for solar energy?

charle [14.2K]

Answer:

Solar panels don't work for every type of roof

Solar isn't ideal if you're about to move

If your electricity costs are low, so are your solar savings

If you can't access solar financing, up-front solar costs can be intimidating

High initial costs for material and installation and long ROI (however, with the reduction in cost of solar over the last 10 years, solar is becoming more cost feasible every day) Needs lots of space as efficiency is not 100% yet. No solar power at night so there is a need for a large battery bank

Besides cost, the single biggest problem with solar is that the sun doesn't shine at night, and it's not guaranteed that it will shine during the day either. This causes several problems, which can be summed up in you not having power when the day ends

Explanation:

Hope this helps:)

4 0

3 years ago

A 9.35g sample of a solid was placed in a 15.00mL flask. The remaining volume was filled with Benzene in which the solid is inso

NikAS [45]

The problem ask to calculate the density of the solid if it has a mass of 9.35g and is place in a 15ml flask. Base on my calculation and further formulation about the density of the two, by subtracting the density of the Benzene, the solid has a density of 1.59g/ml. I hope this would help

3 0

3 years ago

Read 2 more answers

What was the oxygen crisis￼

What was the oxygen crisis