vocab

2. Number – The total number of protons and neutrons in the nucleus.
4. – A neutral particle in the nucleus of an atom.
10. – A negatively charged particle that orbits the nucleus of an atom.
11. – Two or more atoms bonded together.
12. – A substance made of two or more elements that are chemically combined.
13. – A horizontal row on the periodic table; elements in the same period have the same number of energy levels.
14. – The dense center of the atom that contains protons and neutrons.
15. Number – The number of protons in an atom; identifies the element.

1. Electrons – The electrons in the outermost shell of an atom; they determine how an atom bonds.
3. – The smallest particle of an element that still has the properties of that element.
5. Bond – The force that holds atoms together in a molecule or compound.
6. – A positively charged particle in the nucleus of an atom.
7. Table – A chart that organizes all known elements by their properties and atomic number.
8. (Family) – A vertical column on the periodic table; elements in the same group share similar properties.
9. – A pure substance made of only one kind of atom.