It is the mass of one mole of the substance.
Answer:
b. ΔH and ΔS are negative at all temperatures .
Explanation:
During the process of condensation ,
The gaseous state convert to liquid state ,
Hence , the entropy of the system reduces , i.e. , the randomness decreases .
And the value for entropy is negative ,
hence ,
Δ S = negative ,
Δ H = negative ,
Since ,
The heat is releasing from system .
hence , the most appropriate option will be ΔH and ΔS are negative at all temperatures .
a. t=0.553 s
b. vox(horizontal speed) = 3.62 m/s
<h3>Further explanation</h3>
Given
h = 1.5 m
x = 2 m
Required
a. time
b. vo=initial speed
Solution
Free fall motion
a. h = 1/2 gt²(vertical motion=h=voyt+1/2gt²⇒voy = 0)

t = √2h/g
t = √2.1.5/9.8
t=0.553 s
b. x=vox.t(horizontal motion)

vox=x/t
vox=2/0.553
vox=3.62 m/s
The alkaline earth metals (the second group) because their ion charge is +2