Which part of an atom has most of its mass? a. electrons b. neutrons c. nucleus d. protons

The nucleus has most of the atomic mass in an atom. The nucleus is made up of protons and neutrons.

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

d. air pressure decreases as altitude increases.