Periodic table
Across
- 3. these can transmit heat, sound, and electricity
- 4. the most reactive element in group 1
- 7. the vertical columns on the periodic table that indicate reactivity
- 9. a particle smaller than an atom, such as a proton, neutron, or electron
- 11. the most stable group on the periodic table
- 16. negatively charged particles that orbit the nucleus
- 17. a property of metals that allows them to be stretched or hammered into a wire
- 18. the middle of the atom that holds a positive charge and contains protons and neutrons
- 20. 10 protons
- 21. metalloid group 3
Down
- 1. group 1 level of reactivity
- 2. 19 electrons
- 5. nonmetal group 4
- 6. the number of these determines the reactivity of the element; determined by group/family number
- 8. a nonmetal with 8 protons
- 10. determined by subtracting the mass number minus the atomic number (MAN)
- 12. element in group 1 and period 3
- 13. for protons and neutrons it is 1, for electrons it is less than 1
- 14. makes up the mass of an atom with neutrons
- 15. 7 valence electrons and period 5
- 19. the horizontal rows that indicate the number of energy levels or rings