science crossword

3. the chemical element of atomic number 55, a soft, silvery, extremely reactive metal.
5. noble gas that comes from a greek word that means hidden
7. any of a number of subatomic particles carrying a fractional electric charge postulated as building blocks of the hadrons
9. the structure in a cell that contains the chromosomes.
11. the chemical element of atomic number 20, a soft gray metal
13. the chemical element of atomic number 22, a hard silver-gray metal of the transition series, used in strong, light, corrosion-resistant alloys.
15. chemical element whose physical and chemical properties fall in between the metal and non-metal categories
17. a negative charged particle of an atom
18. particles with an electrical charge of 1.
19. a subtance that contains one kinds of atom

1. a chemical element that forms a salt when it reacts with metal.
2. any of a class of substances characterized by high electrical and thermal conductivity as well as by malleability, ductility, and high reflectivity of light.
4. one of 2 elements liquid at room temperature
6. a tool desogned to organize elements
8. neutral particles that do not have an electrical charge.
10. the chemical element of atomic number 88, a rare radioactive metal of the alkaline earth series.
12. Russian chemist who developed a periodic table of the chemical elements and predicted the discovery of several new elements
14. a negatively charged subatomic particle that can be either bound to an atom or free
16. atoms of the same element that have different numbers of neutrons
20. the chemical element of atomic number 3, a soft silver-white metal. It is the lightest of the alkali metals.