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2 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.

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I need help with homework

Aliun [14]

Number 9 is A and 10 is A

5 0

2 years ago

What happens to an endothermic reaction when an equilibrium system is heated?

mina [271]

Answer:

The system shifts forward

Explanation:

The forward reaction is favoured in order to reduce the disruption (excess heat) to the system. Position of equilibrium shifts rightwards of the equation for excess heat to be absorbed during the endothermic forward reaction

8 0

2 years ago

Read 2 more answers

SITUATION # 2: Every morning we drink milk to strengthen our bones. You

hram777 [196]

Answer:

Amount of milk in grams = 95 gram

Explanation:

Given:

Volume of mix solution = 100 ml

Percent of powered milk = 5%

Find:

Amount of milk in grams

Computation:

Assume;

1 ml = 1 gram

Amount of milk = 100 - 100(5%)

Amount of milk = 100 - 5

Amount of milk = 95 ml

Amount of milk in grams = 95 gram

6 0

2 years ago

A sample of nitrogen gas occupies a volume of 2.55 L when it is at 755 mm Hg and 23 degrees Celsius. Use this information to det

ivolga24 [154]

<u>Answer:</u> The number of moles of nitrogen gas are 0.1043 moles and the pressure when volume and temperature has changed is 461.6 mmHg

<u>Explanation:</u>

To calculate the amount of nitrogen gas, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 755 mmHg

V = Volume of the gas = 2.55 L

T = Temperature of the gas = $23^oC=[23+273]K=296K$

R = Gas constant = $62.364\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of nitrogen gas = ?

Putting values in above equation, we get:

$755mmHg\times 2.55L=n\times 62.364\text{ L.mmHg }mol^{-1}K^{-1}\times 296K\\\\n=\frac{755\times 2.55}{62.364\times 296}=0.1043mol$

To calculate the pressure when temperature and volume has changed, we use the equation given by combined gas law.

The equation follows:

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1,V_1\text{ and }T_1$ are the initial pressure, volume and temperature of the gas

$P_2,V_2\text{ and }T_2$ are the final pressure, volume and temperature of the gas

We are given:

$P_1=755mmHg\\V_1=2.55mL\\T_1=23^oC=[23+273]K=296K\\P_2=?\\V_2=4.10L\\T_2=18^oC=[18+273]K=291K$

Putting values in above equation, we get:

$\frac{755mmHg\times 2.55L}{296K}=\frac{P_2\times 4.10L}{291K}\\\\P_2=\frac{755\times 2.55\times 291}{4.10\times 296}=461.6mmHg$

Hence, the number of moles of nitrogen gas are 0.1043 moles and the pressure when volume and temperature has changed is 461.6 mmHg

6 0

2 years ago

Read 2 more answers

Conversion factors are useful in solving problems in which a given measurement must be expressed in

spin [16.1K]

Conversion factors are useful in solving problems in which a given measurement must be expressed in some other units of measure.

Conversion factors are helpful in solving issues where one unit of measurement needs to be expressed in another. In general, a measurement's numerical value changes when it is multiplied by a conversion factor, while the quantity being measured's real size stays the same.
A conversion factor is a number that is used to multiply or divide one set of units into another. If a conversion is required, it must be done using the correct conversion factor to get an identical value. For instance, 12 inches equals one foot when converting between inches and feet.

To learn more about Conversion factors please visit -brainly.com/question/23510660
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4 0

1 year ago

What was the oxygen crisis￼

What was the oxygen crisis