Answer:
A & D
Explanation:
A single-displacement reaction is a chemical reaction whereby one element is substituted for another one in a compound and thereby generating a new element and also a new compound as products.
From the options, only options A & D fits this definition of single-displacement reactions.
For option D: Both left and hand and right hand sides each have one element and one compound. We can see that K is substituted from KBr to join Cl to form KCl and Br2 on the right hand side.
For option A: Both left and hand and right hand sides each have one element and one compound. We can see that OH is substituted from 2H2O to join Mg to form Mg(OH)2 and H2 on the right hand side.
The other options are not correct because they don't involve only and element and a compound on each side of the reaction.
The answer is true: the pressure of a gas will decrease as temperature decreases in a rigid container.
This is one of the central gas laws called the Gay-Lussac law that states for a given gas at a constant volume, the pressure of the gas is directly proportional to its temperature. We also know that as temperature reduces, so too does molecular interaction. Increased temperature results in increased pressure, and decreased temperature therefore results in decreased pressure.
Explanation:
v = wavelength x frequency
330 = 5 . 10-² m x f
f = 6600 Hz
the frequency that human can hear is about 20 Hz - 20000 Hz
so human can hear the note.
Answer:
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Explanation:
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These applications DO NOT INVOLVE harmful ionizing energy:
- MRI
- ultrasound
- laser surgery
