Periodic Table

4. particle, composed of quarks, inside the nucleus of an atom that has a charge of 1+.
5. particles of matter that make up protons and neutrons.
7. uses the symbol for an element and dots representing the number of electrons in the element's outer energy level.
9. area around the nucleus of an atom where the atom's electrons are most likely to be found.
12. table organized list of all known elements that are arranged by increasing atomic number and by changes in chemical and physical properties.
13. positively charged center of an atom that contains protons and neutrons and is surrounded by a cloud of electrons.
15. atoms of the same element that have different numbers of neutrons.

1. weighted-average mass of the mixture of an elements isotope.
2. neutral particle composed pf quarks, inside the nucleus of an atom.
3. horizontal row in the periodic table.; the amount of time it takes one wavelength to pass a fixed point; is expressed in seconds.
6. sum of the number of protons and neutrons in an atom's nucleus.
8. number of protons in an atom's nucleus.
10. particles surrounding the center of an atom that have a charge of 1-.
11. vertical column in the periodic table.
14. the smallest particle of an element that still retains the properties of the element.