A 0.2-kilogram disk sliding at 8 meters per second on a table with negligible friction, as shown, strikes a 1.0-kilogram disk sliding at 2 meters per second in the same direction. After the collision, the 0.2-kilogram disk slides backward at 2 meters per second. What is the speed of the 1.0-kilogram disk after the collision?

Match each vocabulary term to its definition. 1. electrons neutral subatomic particles found in the nucleus of the atom 2. neutron lowest energy position of an electron in an atom 3. photon the path of an electron around the nucleus of an atom 4. ground state negatively charged, subatomic particles 5. protons packet of energy of specific size 6. element substance with only one type of atom 7. orbital positively charged, subatomic particles found in the nucleus of the atom