Crossword Puzzle for school.

12345678910111213141516171819202122232425
Across
  1. 4. metals consist of the chemical elements lithium, sodium, potassium, rubidium, caesium, and francium.
  2. 6. are a group in the periodic table consisting of five chemically related elements: fluorine, chlorine, bromine, iodine (I), and astatine.
  3. 8. is a type of chemical element which has properties in between, or that are a mixture of, those of metals and nonmetals.
  4. 10. one of two or more species of atoms of a chemical element with the same atomic number.
  5. 11. Negative ions are odorless, tasteless, and invisible molecules that we inhale in abundance in certain environments.
  6. 13. A particle that has a positive charge.
  7. 14. Is a symbol that represents the Atomic ______ unit.
  8. 17. Are one of the ways that the periodic table is organized, There are 18 of them.
  9. 18. is an element that readily forms positive and has metallic bonds.
  10. 21. is the process by which an unstable atomic nucleus loses energy by radiation.
  11. 23. a particle that has NO charge.
  12. 24. formed by atoms or molecules suffering an inelastic collision.
  13. 25. a particle that has a negative charge.
Down
  1. 1. Is a Group(2) that consists of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
  2. 2. the central and most important part of an object.
  3. 3. is a chemical element that mostly lacks the characteristics of a metal.
  4. 5. 38 elements in groups 3 through 12.
  5. 7. a group of 15 chemical elements, with atomic numbers 57 through 71.
  6. 9. is a particle, atom, or molecule with a net electrical charge.
  7. 12. six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).
  8. 15. the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei.
  9. 16. represents the area around the nucleus of an atom.
  10. 19. Are one of the ways that the periodic table is organized, There are seven of them.
  11. 20. the number of protons in the nucleus of an atom.
  12. 22. a series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103.