Manometer
An instrument used to measure the pressure of a gas.
Mass
A physical property representing the amount of matter in a given sample.
Mass defect
The difference between the sum of the masses of neutrons and protons forming a nucleus and the
mass of that nucleus; the mass equivalence of binding energy, with the two related via the equation
E = mc^2.
Mass number
The total number of protons and neutrons in a nucleus.
Maxwell-Boltzmann distribution
The distribution of the molecular speeds of gas particles at a given temperature.
Melting point
The temperature at which the solid and liquid phases of a substance coexist in equilibrium.
Metal
One of a class of elements located on the left side of the periodic table, possessing low ionization
energies and electronegativities. Metals readily give up electrons to form cations; they possess
relatively high electrical conductivity and are lustrous and malleable.
Metallic bonding
The type of bonding in which the valence electrons of metal atoms are delocalized throughout the
metallic lattice.