Usually, percent yield is lower than 100% because the actual yield is often less than the theoretical value. Reasons for this can include incomplete or competing reactions and loss of sample during recovery. Percent yield is always a positive value. I hope this can help you
Answer:
finely divided iron is used as catalyst in the manufacture of ammonia by haber's process
Based on these findings, Einstein proposed that light behaved as a stream of photons with an energy.
Kinetic energy, Ek = ½mv^2 where m is mass and v is velocity.
Ek = m[v^2 – u^2]/2 and assuming u = 0,
Ek = ½mv^2
<h3>What is the photoelectric effect?</h3>
When light shines on a metal, electrons are ejected from the metal's surface, causing the photoelectric effect. This is referred to as photoemission, and the electrons released from the metal are referred to as photoelectrons. Photoelectrons behave and have the same properties as ordinary electrons. The photo- prefix simply signifies that incoming light has released electrons from a metal surface.
To explain the photoelectric effect, 19th-century scientists hypothesised that the fluctuating electric field of the incoming light wave heated the electrons and drove them to vibrate, eventually freeing them off the metal surface.
Learn more about photoelectric effect refer:
brainly.com/question/21320305
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Answer:
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Explanation:</h2><h3><em>use molar mass to finf moles of O2:
</em></h3><h3><em>
5.3 g O2 32.0 g/mol = 0.1656 moles of O2
</em></h3><h3><em>
use this ratio: 4NH3(g) + 7O2(g) --> , to find moles of NH3:
</em></h3><h3><em>
0.1656 mol O2 4 mole NH3 / 7 mol O2 = 0.09464 moles of NH3
</em></h3><h3><em>
using the "molar volume " ratio for gases STP, find the litres of NH3:
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0.09464 moles NH3 22.4 litres / mole STP = 2.12 litres
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</em>
<u><em>answer: 2.1 litres</em></u>
Answer:
D. One variable should change and the others should be kept the same
Explanation:
Variable in an experiment are defined as the things that changes. There are three variables in an experiment: dependent, independent, and controlled.
Independent variable is defined as the variable which is changed by researcher during an experiment and it influence the dependent variable to be changed. Controlled variables are required to be constant in an experiment and observe them carefully.
In an experiment, it is important to change only one variable that is independent variable because changing other variables can make the result confusing and if only one variable will be changed, it would be easy to observe changes in other variables.
Hence, the correct answer is "D. One variable should change and the others should be kept the same".