Chemistry vocabulary

3. mass number, the total number of protons and neutrons is an atom's nucleus
5. an atom that has a postive or negative electric charge
8. , the lengh of time it takes for half of the atoms in a sample of a radioactive element to decay into atoms of another element.
9. , an atom of one element that has a different number of neutrons than another atom of the same element
10. a vertical column in the periodic table of the elements . Elements in a group have similar properties
11. , an element that has properties of both metals and nonmentals
13. , The structure in a eukaryotic cell that contains the genetic material a cell needs to reproduce and function .
14. table , a table of elements , arranged by atomic number, that shows the patterens in there properties

1. A hortizontal row in periodic table of elements. Elements in a period have verying properties
2. and element that is not a mental and has properties generally oppisite to those mental
3. Number, The number of protons and neutrons is an atom's nucleus
4. an element that tends to be shiny,easily shaped , and a good conductor of electricity and heat
6. , A positively charged particle located atoms nucleus.
7. , A particle that has no electric charge and is located in an atom nucleus
12. , A negatively charged particle located outside an atom’s nucleus An electron that is 2000 times smaller than a proton or neutron