In the reaction shown, iron reacts with water to form iron oxide (Fe, 04) and hydrogen gas (H,). 3Fe + 4H20
Fe304 + 4H2
Which of these BEST describes the iron (Fe) reactant?
O
A. molecule
B. ion
o
C. compound
O
D. element

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i.e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.

The law of the conservation of momentum says that the total momentum of any closed and isolated system cannot

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)