4. describe three ways carbon dioxide was removed from the Earth's atmosphere.
Answer: Forests: Photosynthisis helps clear carbon dioxide naturally, Soils naturally store carbon, but agricultural soils are running a big deficit due to intensive use. Because agricultural land is so expansive, Bio-energy with Carbon Capture and Storage (BECCS) is another way to use photosynthesis to combat climate change. However, it is far more complicated than planting trees or managing soils — and it doesn’t always work for the climate.
5. Explain why there is now 21% Oxygen in the Earth's atomosphere compaired to little or no Oxygen in the Earth's atmosphere 4.5 billion years ago.
Answer: cientists believe that the Earth was formed about 4.5 billion years ago. Its early atmosphere was probably formed from the gases given out by volcanoes. It is believed that there was intense volcanic activity for the first billion years of the Earth's existence.The early atmosphere was probably mostly carbon dioxide, with little or no oxygen. There were smaller proportions of water vapour, ammonia and methane. As the Earth cooled down, most of the water vapour condensed and formed the oceans.
Sorry its soooo long TwT
Answer : The % of (+) limonene isomer = 79%
The % of (-) limonene isomer = 0%
The % of enantiomeric excess = 58%
Explanation : Enantiomeric excess (ee) is the measurement of purity used for chiral substances.
Given,
% of pure limonene enantiomer = The % of (+) limonene isomer = 79%
Therefore, The % of (-) limonene isomer = 0%
Formula used :
Where, ee → enantiomeric excess
Now, put all the values in above formula, we get the value of enantiomeric excess (ee).
= 58%
Answer:
= 62.1 hours
Explanation:
Energy provide by the serving is 65 cal
= 65 cal × 4.184 Kj = 271.96 kJ
271.96 KJ = 271960 J
Energy required for 1minute of energy
= 73 x 1
= 73 J/min
So, 271960 joules will be required for 271960 heart beat
Minutes = 271960 / 73
= 3593.94 minutes
Time in hours = 3725.429 / 60
= 62.1 hours
Formula units in 450 g of 
is 1.93 × 10²⁴ formula units.
<u>Explanation:</u>
First we have to find the number of moles in the given mass by dividing the mass by its molar mass as,
Now, we have to multiply the number of moles of Na₂SO₄ by the Avogadro's number, 6.022 × 10²³ formula units/mol, so we will get the number of formula units present in the given mass of the compound.
3.2 mol × 6.022 × 10²³ = 1.93 × 10²⁴ formula units.
So, 1.93 × 10²⁴ formula units is present in 450g of Na₂SO₄.
