chemistry 1

4. the number of protons in the nucleus of an atom
7. The total number of protons and neutrons in an atom's nucleus
10. The length of time it takes for the atoms in a sample of a radioactive element to decay into an atom of another element
12. An atom or group of atoms that has a positive or negative electric charge
13. A positively charged particle located in the atom's nucleus
14. A horizontal row in the periodic table of elements. Elements in a period have varying properties
15. A table of elements, arranged by atomic number, that snows the patterns in their properties

1. An element that is not a metal and has properties generally opposite to those of a metal
2. A particle that has no electric charge located in the atom's nucleus
3. A vertical column in the periodic table of elements. Elements in this group have similar properties
5. An element that tends to be shiny, easily shaped, and a good conductor of heat and electricity
6. The central region of an atom where most of the atom's mass is found in protons and neutrons
8. An element that has properties of both metals and nonmetals
9. A negatively charged particle located outside an atom's nucleus
11. An atom of one element that has a different number of neutrons than another atom of the same element