Answer:
Hydrogen
Explanation:
Balloons are filled with light gases in order to make them float. Helium and Hydrogen are both light gases.
Helium is quite a lot lighter than air: it's about an eighth of the density of air. Hydrogen is about a sixteenth the density of air, so it'll float in air and will in fact float upwards.
Hydrogen however is twice as heavy as helium, but that doesn't mean the amount of lift off of the balloon is twice as much. The amount of lift is determined by the difference in density with respect to air.
Hydrogen is calculated to be less dense than helium, that explains why hydrogen filled balloons would go up higher.
Helium filled balloons are used because of the safety implications. The problem is that hydrogen is explosive may have some health and safety implications! Helium is much more safe to use.
Answer: subduction and sea floor spreading
Explanation:
He knew that the continents today were once joined together by fossil records of plants and animals that were found to be on continents far removed from each other. He knew this also by corresponding land forms that matches up as well. What he couldn’t prove is how the land masses would have moved so far away from each other. Subduction and sea floor spreading move the tectonic plates that the continents sit on. That’s what he was missing.
The red colour is the limiting reactant.
Red-blue colour ball and two white balls attached together are reactants.
Red-blue colour ball and two white and one red colour ball attached to each other are products.
<h3>What is a limiting reagent?</h3>
The reactant that is entirely used up in a reaction is called a limiting reagent.
A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products.
A product is a substance that is present at the end of a chemical reaction.
Hence,
The red colour is the limiting reactant.
Red-blue colour ball and two white balls attached together are reactants.
Red-blue colour ball and two white and one red colour ball attached to each other are products.
Learn more about limiting reagents here:
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Explanation:
from the graph study about oxygen content of Earth's atmosphere, we can understand that
1)
4 billions year ago = None, 3 billions year ago = Cyanobacteria and Archaea , 2 and 1 billions year ago = Bacteria and Green algae , 500 Ma = invertebrate fossils started to existence. Early land plants came in to existence around 398 MA that is Devonian. Dinosaurs are came in to existence during Triassic and Jurassic that is around 251 Ma. Man and animals are recent organism came under Holocene that is 11000 years ago.
2)
The first cells on the earth are anaerobic microorganisms, as the CO2 level is too high they survive by using CO2.
3)
Starting around 2.7 billion years ago, photosynthesis by Cyanobacteria and later plants , pumped “OXYGEN” in to the atmosphere. This caused the decline of anaerobic bacteria and allows the diversification of animals as seen in “CAMBRIAN” around 500 millions year ago.
Early vascular plants “CAPTURED” CO2 starting before the Carboniferous period that began around 350 millions year.Leading to lower temperatures and allowing and allowing the seed plants to outcompetes seedless plants.
Modern human activities has raised both “CO2 and METHANE” level in the atmosphere to over leading to higher temperature and extinction of other species.
The term sensitivity in Analytical Chemistry is "the slope of the calibration curve or a function of analyte concentration or amount".
<u>Answer:</u> Option B
<u>Explanation:</u>
In a sample, the little amounts of substances can be accurately evaluated by a method is termed as "Analytical sensitivity". This detect a target analyte like an antibody or antigen, process is considered as potential of a test to and generally demonstrated as the analyte's minimum detectable concentration.
The acceptable diagnostic sensitivity is not guaranteed by high analytical sensitivity. The percentage of individuals who have a given disarray who are identified by the method as positive for the disarray is known as "Diagnostic sensitivity".