Which substance shown has the greatest kinetic energy at room temperature (~25°C)?
(1 point)
Responses
silicon
silicon
methane
methane
mercury
mercury
helium
helium
1.helium
2.solid, liquid, gas
3.the energy an object has because of its motion
4.the measure of the average kinetic energy of particles in an object due to motion
5.solid
silicon
To determine which substance has the greatest kinetic energy at room temperature, we need to consider their molecular mass and the temperature.
The formula to calculate kinetic energy is given by:
KE = (3/2) * k * T
Where:
KE is the kinetic energy
k is the Boltzmann constant (1.38 * 10^-23 J/K)
T is the temperature in Kelvin
Let's convert the temperature from Celsius to Kelvin by adding 273 to the value:
Room Temperature (25°C) = 25 + 273 = 298 K
Now, let's calculate the kinetic energy for each substance:
Silicon:
Molecular mass (m) = 28.0855 g/mol
KE_silicon = (3/2) * (1.38 * 10^-23 J/K) * 298 K = 6.16 * 10^-21 J
Methane:
Molecular mass (m) = 16.043 g/mol
KE_methane = (3/2) * (1.38 * 10^-23 J/K) * 298 K = 3.47 * 10^-21 J
Mercury:
Molecular mass (m) = 200.59 g/mol
KE_mercury = (3/2) * (1.38 * 10^-23 J/K) * 298 K = 2.59 * 10^-20 J
Helium:
Molecular mass (m) = 4.003 g/mol
KE_helium = (3/2) * (1.38 * 10^-23 J/K) * 298 K = 1.25 * 10^-20 J
Comparing the calculated kinetic energies, we can conclude that Mercury (Hg) has the greatest kinetic energy at room temperature (~25°C).