A) -0.5(9.8)*t^2 = -25(t-2) - 0.5(9.8)(t-2)^2
-4.9t^2 = -25t + 50 - 4.9(t^2-4t+4)
0 = -25t+50+19.6t - 19.6
5.4t = 30.4
t = 5.62962963 s
b) h = -4.9(5.62962963)^2
h = -155.2943759
the building is 155.2943759 m high
c) speed 0of first stone
= at
= 9.8*5.62962963
= 55.17037037 m/s
speed of second stone
= v + at
= 25+9.8*3.62962963
= 60.57037037 m/s
The way I would explain it is quite difficult to understand, so this is what Google says. "The wavelength (or equivalently, frequency) of the photon is determined by the difference in energy between the two states. These emitted photons form the element's spectrum. The fact that only certain colors appear in an element's atomic emission spectrum means that only certain frequencies of light are emitted." I hope this helped.
Answer is: reducin agent in this reaction is thiosulfate (S₂O₃²⁻).
Balanced chemical reaction: 2S₂O₃²⁻(aq) + I₂(aq) → S₄O₆²⁻(aq) + 2I⁻<span>(aq).
Reducing agent is element or compound who loose electrons in chemical reaction. Sulfur in </span>thiosulfate change oxidation number from +2 to +5 tetrathionate anion (two<span> sulfur </span>atoms in the ion have oxidation state<span> 0 and two atoms have oxidation state +5).</span>
First convert grams to moles
using molar mass of butane that is 58.1 g
3.50g C4H10 x (1 mol
C4H10)/(58.1g C4H10) = 0.06024 mol C4H10 <span>
<span>Now convert moles to molecules by using Avogadro’s number
0.06024 mol C4H10 x (6.022x10^23 molecules C4H10)/(1 mol
C4H10) = 3.627x10^22 molecules C4H10
And there are 4 carbon atoms in 1 molecule of butane, so use
the following ratio:
3.627 x 10^22 molecules C4H10 x (4 atoms C)/(1 molecule
C4H10)
<span>= 1.45 x 10^23 atoms of carbon are present</span></span></span>