mass

The intrinsic property of matter that resists acceleration and generates gravity.

• inertial mass: resistance to change in momentum under applied force
• gravitational mass: source of and response to gravity — equivalent to inertial mass
• related to energy by E = mc² — see relativity
• Higgs field gives elementary particles their rest mass
• momentum equals mass times velocity — see momentum
• determines curvature of spacetime in general relativity
• conserved in closed systems alongside energy and momentum