A weather balloon filled with helium has a volume of 700 L at STP. To find the mass of helium which conversion factors would you use A) 22.4 L/mol x 4 g/mol
B) 700 L / 4 g/mol
C) (22.4 L/mol / 700 L ) / (4 g/mol)
D) (700 L / 22.4 L/mol) (4 g/mol)

D: (700 L / 22.4 L/mol) (4 g/mol)

Explanation:

At STP, Molar volume of a gas = 22.4 L/mol

Now, we are told that helium has a volume of 700 L at STP.

Also, atomic mass of helium = 4 g/mol

Thus, the mass of helium is given as;

(700 L/22.4 L/mol) × 4 g/mol

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

i think that the answer is c