The arrows that represent the phase transitions in which heat energy is gained is : (A). 1, 2 and 3
<h3>Meaning of phase transitions</h3>
Phase transitions can be defined as the changing of matter from one form to another due to the addition or gaining of heat or due to the removal or loss of heat.
Phase transitions in matter are majorly between three phases which are: Solid, Liquid and Gas.
In conclusion, The arrows that represent the phase transitions in which heat energy is gained is : (A). 1, 2 and 3
Learn more about Phase transitions: brainly.com/question/11048831
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The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
Volume of Hydrogen V1 = 351mL
Temperature T1 = 20 = 20 + 273 = 293 K
Temperature T2 = 38 = 38 + 273 = 311 K
We have V1 x T2 = V2 x T1
So V2 = (V1 x T2) / T1 = (351 x 311) / 293 = 372.56
Volume at 38 C = 373 ml