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
ideal gas law. but you are talking about moles of gas not miles
Since phosphorus is in the 5th group it has the ability to gain or lose electrons
A is correct hope this helps