Across
- 3. the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus.
- 5. the quantity of matter contained in an atom of an element.
- 8. is a planetary model in which the negatively charged electrons orbit a small, positively charged nucleus similar to the planets orbiting the sun
- 10. shows a particular area in which an electron is likely to be.
- 11. neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen.
Down
- 1. in nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.
- 2. stable subatomic particle that has a positive charge equal in magnitude to a unit of electron charge
- 4. is one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table
- 5. is the basic building block of chemistry. It is the smallest unit into which matter can be divided without the release of electrically charged particles.
- 6. is the main control center for the cell and acts kind of like the cell's brain
- 7. lightest stable subatomic particle known it carries a negative charge
- 9. is one of the stable states of constant energy that may be assumed by a physical system