Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =
Using the formula
Number of moles of NaOH

Molar mass of water=16+2(1.01)=18.02g
Number of moles of water

Now, mole fraction of NaOH
=

=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
That is false because aluminum melts at 2,470C
Electrons are emitted from the surface of a metal in photoelectric effect.
<h3>What is the photoelectric effect?</h3>
The photoelectric effect is the emission of electron from the surface of a metal when light is shone on the surface..
For electrons to be emitted, the light must have a certain frequency known as threshhold frequency.
Therefore, electrons are emitted from the surface of a metal in photoelectric effect.
Learn more about photoelectric effect at: brainly.com/question/21320305
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Answer:
the blanket of gases that surrounds Earth and some other planets
Explanation:
The best definition of the atmosphere is that it is a portion of the earth that is a made up of a blanket of gases.
- The atmosphere is not peculiar to the earth alone, some other planets also have atmospheric cover.
- The earth's atmosphere is divided into many different layers.
- The weather we see and experience on the earth surface is conditioned within the troposphere.
- This troposphere is the closest layer to the surface.