C because
Explanation Plato
The reactivity of metals increases as you move left in a period and as you move down in a group, so Marie needs to know the period and group of the element inside each box. Boxes that show locations in groups 1 or 2 or in period 8 contain the most reactive elements.
60 g C2H6 × 1 mol C2H6 x 7 mol O2 x 32 g O2 = ~223.5 g O2
30.068 g 2 mol C2H6 1 mol O2
Answer: 2m/s^2
Explanation:
Velocity of skateboard = 20.0 m/s.
Time taken = Ten seconds (10 s)
Acceleration = ?
Recall that acceleration is the change in velocity of a body per unit time.
i.e Acceleration = (velocity / Time)
Acceleration = 20.0m/s ➗ 10 s
Acceleration = 2m/s^2
Thus, Jeffrey acceleration was 2m/s^2