The Structure of an Atom

1. The Structure of an Atom Chapter 4.2

2. Warm-up:KWL Chart - ATOMS

3. Properties of Subatomic Particles • There are 3 types of subatomic particles in an atom • Protons • Electrons • Neutrons

4. Protons • POSITIVELY charged particle located in the nucleus of an atom • Each element contains at least 1 proton • Each proton has a charge of +1 • Rutherford discovered that the amount of positive charge varies among elements

5. Electrons • NEGATIVELY charged subatomic particle that is found in the space outside the nucleus • Each electron has a charge of 1- • Its mass is so small that it is not taken into consideration

6. Neutrons • Neutral subatomic particle that is found in the nucleus of an atom. • Its mass is almost exactly equal to that of a proton

7. Comparing Subatomic Particles • Protons, Neutrons, and Electrons can be distinguished by mass, charge, and location in the atom

8. Fun Facts About Atoms

9. Atomic Number • Atomic number of an element is equal to the number of protons in the nucleus of that element • Atomic number = # protons • Atoms of different elements have different numbers of protons

10. Electrically Balanced Atoms • The number of protons in an atom is balanced by the number of electrons in the atom so that the atom does not carry a net charge • So, the atomic number also tells us the # of electrons

11. Mass Number • Mass number = # protons + # neutrons (in the nucleus of an atom)

12. Calculating the Number of Neutrons • Number of Neutrons = Mass number – Atomic Number

13. Isotopes • Isotopes are atoms of the same element that have different numbers of neutrons • Isotopes of an element have the same atomic number, but different mass numbers because they have different numbers of neutrons

14. More About Isotopes..

15. Carbon Isotopes