1. Atoms,and Elements
Atoms

2. A) All Matter is made of Atoms

3. 1) An atom is the smallest unit of pure substance that still has the properties of the substance

4. 2) Atomic Theory states that all matter is made up of atoms
2) Atomic Theory states that all matter is made up of atoms. It is supported by John Dolton’s experiments

5. 3) J.J. Thomson’s Plum Pudding model of the atom included subatomic particles

6. 4) Ernest Rutherford’s Modern Atomic Model includes protons, neutrons, and electrons

7. a) Nucleus: center of the atom

8. i) Proton: Positive electrical charge

9. ii) Neutron: No electrical Charge (neutral)

10. b) Electrons: negatively charged particles circling the nucleus in an area called the electron cloud

11. B) The Nucleus

12. 1)Rutherford discovered that most of the atom is empty space

13. 2) Nucleus is 1/10,000 the diameter of the atom (tennis ball nucleus to half mile diameter of atoms)

14. 3) Nucleus is 99.9 percent the mass of the atom

15. 4) Number of protons determines the type of atoms (each atoms has a different number of protons)

16. 5) Example Hydrogen has only one proton, Oxygen has Eight Protons

17. 6) Atomic Number: the number of protons in an atoms

19. C) Isotopes: Atoms with the same number of protons but different number of neutrons

20. 1) Mass of an atom is measured in Atomic Mass Units (Protons = 1amu and Neutrons = 1amu)

21. 2) Atomic Mass is the number of protons and neutrons

22. D) Charges in Atoms

23. 1) The positive electric charge of the protons holds the negatively charged electrons spinning around the nucleus

24. 2) Nucleus held together by force called strong nuclear force

25. 3) Atoms start with the same number of Protons and Electrons

26. 4) Ion: an atom with an electrical charge created by gaining or losing electrons