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The partial pressure of helium to keep the partial pressure of oxygen at 0,21 atm in a scuba-diver tank is
8,09 atmTo solve this question, we can use the
Dalton's Law, which states that the total pressure in a container with a mixture of gases is the sum of the partial pressures o each individual gas. For the case of this mixture the Dalton's Law is as follows:

In this equation, we need to clear for PHe, knowing that the PO₂ should be 0,21 atm, to find the required pressure of Helium:

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Answer:Answer: Mendeleev's table of elements was better accepted than those of other scientists at the time because it predicted correctly the properties of elements that had not yet been discovered. Moseley went a step further in suggesting that the elements be arranged according to atomic number
Explanation:
Answer:
Height = 1.9493 cm
Width = 1.9493 cm
Depth = 1.9493 cm
Solution:
Data Given:
Mass = 20 g
Density = 2.7 g/mL
Step 1: Calculate the Volume,
As,
Density = Mass ÷ Volume
Or,
Volume = Mass ÷ Density
Putting values,
Volume = 20 g ÷ 2.7 g/mL
Volume = 7.407 mL or 7.407 cm³
Step 2: Calculate Dimensions of the Cube:
As we know,
Volume = length × width × depth
So, we will take the cube root of 7.407 cm³ which is 1.9493 cm.
Hence,
Volume = 1.9493 cm × 1.9493 cm × 1.9493 cm
Volume = 7.407 cm³
You would want to make sure that you have controlled the variables properly, and if you determine that you did then you would repeat the experiment to be sure of the results.
<u>Stimulants </u> often cause overactive eye movement
Ans (A)
Stimulants are a class of psychoactive drugs that increase the brain activity. They work by acting on the central nervous system and increase the level of mental alertness and impart heightened cognitive functions. Stimulants like nicotine and cocaine cause overactive eye movement.