Exploring Subatomic Particles in Atoms: The Basics Unveiled

1. Unit 3: The Atom

2. Atoms • All matter is made of very tiny particles • These particles have the same properties as the matter has

3. Parts of the Atom • Subatomic Particles – smaller than an atom • Proton • Neutron • Electron

4. Subatomic Particles • Protons • Positive charge • Each one has a charge of +1 • Located in the nucleus • Each one has a mass of 1amu (atomic mass unit)

5. Subatomic Particles • Neutrons • No charge • Located in the nucleus • Each one has a mass of 1amu (atomic mass unit)

6. Subatomic Particles • Electrons • Negative charge • Each one has a charge of -1 • Located in the space around the nucleus • Each one has a mass of about 0.0006amu (atomic mass unit)

7. The Atom

8. The Atom • The nucleus has protons and neutrons • Positively charged • The electron cloud has electrons • Negatively charged • The number of protons equals the number of electrons in a neutral atom

9. Periodic Table • The periodic table gives us lots of information about the elements. 1 H Hydrogen 1.008 Atomic Number Element Symbol Element Name Average Atomic Mass

10. Symbol Practice For the element name, give the symbol. Helium Carbon Sulfur Oxygen Magnesium

11. Element Practice For the symbol, give the element name. Li N Ar Al Na

12. Atomic Number • Atoms of different elements are different • All protons and neutrons are identical to each other • The number of protons in the nucleus explains the difference • The number of protons in the nucleus is the atomic number of an element

13. Atomic Number • The atomic number identifies the element • Like DNA for an element • Examples: • Hydrogen atoms and only hydrogen atoms have 1 proton in the nucleus • Helium atoms and only helium atoms have 2 protons in the nucleus

14. Proton Practice Practice: How many protons are in each of the following elements? Carbon Potassium Nitrogen Calcium Silicon

15. Electrons • Electrons give atoms their chemical properties • In order for an atom to have a neutral charge, it must have the same number of electrons as it has protons. • Electrons = protons = atomic number

16. Electron Practice Practice: How many electrons are in each of the following elements? Helium Chlorine Nitrogen Aluminum Boron

17. Mass Number • All atoms have a mass number • We can figure it out by rounding the Average Atomic Mass to the nearest whole number • Mass number = protons + neutrons • Neutrons = Mass number – protons

18. Finding Neutrons • Example: Carbon • Round the Average Atomic Mass to the nearest whole number: 12.01 rounds to 12 • How many protons in carbon? 6 • Neutrons = Mass number – protons Neutrons = 12 – 6 = 6

19. Neutron Practice Practice: How many neutrons are in each of the following elements? Oxygen Chlorine Argon Aluminum Phosphorus

20. Atom Concept Map

21. First 25 Elements Activity

22. Isotopes • Isotopes of an element have the same number of protons, but different numbers of neutrons. • There can be many isotopes of the same element.