Technically, the answer is iron. Oxygen has a melting point way below zero (-219 degrees celsius), ice becomes water AT room temperature and bromine is already a liquid at room temperature. So, iron has a melting point greater than room temperature due to the fact that metals are made up of giant structures of atoms in a regular arrangement, and there are strong forces of electrostatic attraction between positive metal ions and negative electrons, meaning that a lot of heat energy is required to break the bonds, i.e. a very high melting point, approx. 1500 degrees celsius. Hope this helps.
21.4 g Al * (1 mol / 26.98 g ) * (2 mol Fe / 2 mol Al) = 0.793 mol Fe
91.3 g Fe2O3 * (1 mol / 159.69 g) * (2 mol Fe / 1 mol Fe2O3) = 1.14 mol Fe
0.793 mol Fe * (55.85 g / 1 mol) = 44.3 g Fe produced.
Height of wave - amplitude
Higher the pitch - higher the frequency
Louder - higher the amplitude
bottom of the wave - trough
distance from crest to crest - wave length
top of the wave - crest
F = (mass)(acceleration) = ma
m = 55 kg
Vi = 20 m/s
t = 0.5 s
Vf = 0 m/s (since she was put to rest)
a=(Vf-Vi)/t
a=(0-20)/5
a = 40 m/s^2 (decelerating)
F = ma = (55 kg)(40 m/s^2)
F = 2200 N
