Science

3. -a horizontal row in the periodic table of the elements
4. -any of the six chemical elements that make up Group 1
8. -any atom or group of atoms that has a positive or negative electric charge
10. - a vertical column in the periodic table
14. - If it has more protons than electrons
15. -a particle that surrounds the nucleus, with a negative charge
16. -An atomic or molecular system having an excess of negative charge
18. -the process by which the nucleus of an atom of an element
20. -1/12 the mass of a carbon-12 atom
21. -an element that tends to be shiny and easily shaped
22. -a particle found in the nucleus with a positive charge
23. -a particle found in the nucleus with a neutral charge
24. -the chemical elements that are present in the 17th group of periodic table

1. -Atoms with the same number of protons but different numbers of neutrons
2. -an element that has properties of both metals and nonmetals
4. -the number of protons in the nucleus of an atom
5. - the elements that correspond to group 2 of the modern periodic table
6. -the emission of energy in the form of ionizing radiation
7. - an element that is not a metal
9. -any of a group of rare gases
11. -the members of the 15 naturally occurring metallic chemical elements
12. - any of various metallic elements that have valence electrons in two shells instead of only one
13. - A group of electrons circulating around a nucleus
17. -the central region of an atom where most of the atom's mass is found in protons and neutrons
19. -any of the series of elements with increasing atomic numbers that begins with actinium or thorium and ends with lawrencium