Answer:
C. 
Explanation:
Molecules with the stronger intermolecular forces are pulled tightly together to form solid at higher temperatures and that's why the freezing point is higher.
Also, molecules with the stronger intermolecular force have greater interaction between the molecules and thus on heating do not boil easily and have high boiling point also.
Thus, melting point and boiling point increases with increase in number of carbon atoms and also increase in intermolecular forces (like hydrogen bonding, if present).
Thus, the compound which is gas at room temperature is
<u>because it has least number of carbon atoms and absence of hydrogen bonding.</u>
<u></u>
The time elapsed when the ball placed above the concave mirror and the image formed would be at the same location is 0.55 s.
<h3>Image distance</h3>
The position of the image formed is determined using the followimg mirror formula;

where;
- f is the focal length of the mirror
- v is the image distance
- u is the object distance
f = R/2
f = 1.5/2
f = 0.75 m
When the ball and its image is in the same position, u = v
The position of the ball is calculated as;

<h3>Time of motion of the ball</h3>
The time taken for the ball to travel the caluclated distance is determined as;
h = ut + ¹/₂gt²
1.5 = 0 + ¹/₂(9.8)t²
1.5 = 4.9t²
t² = 1.5/4.9
t² = 0.306
t = 0.55 s
Thus, the time elapsed when the ball and its image are at the same location is 0.55 s.
Learn more about concave mirror here: brainly.com/question/7512320
Molar mass NaOH = 39.997 g/mol
Number of moles :
n = mass of solute / molar mass
n = 11.5 / 39.997
n = 0.287 moles
Therefore :
Molarity = moles solute / volume
Molarity = 0.287 / 1.5 => 0.1913 M
Answer:air, water, and organisms in water
Explanation:
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