Chemistry

3. an element that tends to be shiny, easily shaped, and a good conductor of electricity and heat
4. a horizontal row in the periodic table of the elements; elements in a period have varying properties
8. an element that is not a metal and has properties generally opposite to those of a metal
9. table, a table of elements, arranged by atomic number, that shows the patterns in their properties
12. a negatively charged particle located outside an atom's nucleus, An electron is about 2000 times smaller than either a proton or neutron
14. number the number of protons in the nucleus of an atom
15. The central region of an atom where most of the atom's mass is found in protons and neutrons

1. the length of time it takes for half of the atoms in a sample of a radioactive element to decay into atoms of another element
2. an element that has properties of both metals and nonmetals
5. an atom or group of atoms that has a positive or negative electric charge
6. a particle that has no electric charge and is located in an atom's nucleus
7. mass number the total number of protons and neutrons in an atom's nucleus
10. an atom of one element that has a different number of neutrons than another atom of the same element
11. a positively charged particle located in an atom's nucleus
13. a vertical column in the periodic table of the elements; elements in a group have similar properties