science

3. The number of protons in the nucleus.
7. He proposed that electrons travel in defined circular orbits around the nucleus.
8. A horizontal row in the periodic table.
9. A bond involving a "sea of electrons" around metal atoms.
11. A particle that can be found in the nucleus.
12. A vertical column in the periodic table.
15. He stated that everything is composed of 4 kinds of matter.
21. The regions of space with high probability of finding electrons.
22. The negative charged subatomic particle.
24. Atoms of the same element with different numbers of neutrons.
25. A substance made of two or more different elements.
27. A pure substance made of only one kind of atom.
28. The splitting of a heavy atomic nucleus.
29. The total number of protons and neutrons in an atom.
30. A region around an atom's nucleus where electrons are most likely to be found.

1. In this model, it is proposed that instead of orbits, there were orbitals or region of space with high probability of finding electrons.
2. He stated that substances have infinitesimally small particles.
4. An atom that gained or lost electrons, giving it a charge.
5. A group of atoms bonded together.
6. The simplest and most abundant chemical element in the universe.
10. How strongly an atom attracts electrons.
13. The positive charged subatomic particle.
14. A device used for artificially transmuting one element into another.
16. The joining of two atomic nuclei.
17. The subatomic particle located in the nucleus that does not have any change.
18. Number of electrons in the outer shell.
19. Referring to particles smaller than atoms.
20. A type of bond where atoms share electrons.
23. The dense center of an atom containing protons and neutrons.
26. He developed and published a periodic table of elements showing elements in order based on their atomic weights.