2. Chemistry

3. Chemistry  Chemistry is the study of composition, structure, and properties of matter and their chemical reactions. The top picture is of cellulose (plant sugar) on a molecular level.The top picture is of cellulose (plant sugar) on a molecular level. The bottom picture is cotton.The bottom picture is cotton.

4. Matter is in everything and a part of everything.  Matter is anything that has mass and volume. Mass is the quantity of matter.Mass is the quantity of matter.  How much stuff is in something. Measured in Kg.Measured in Kg. Volume is the amount of space an object takes up.Volume is the amount of space an object takes up.  Measured in L or m 3

5. Mass is a quantity of matter, but what are we talking about?  We are talking about atoms.  Everything is made of atoms even air.  Atoms are so small we can’t see them, not even with a microscope.

6. The Size of the Atom  The width of the human hair is 1 million carbon atoms wide.  2x10 21 atoms in a drop of water.  2,000,000,000,000,000,000,000

7. Atom  The atom is a basic unit of matter. If you take a substance and could keep cutting it up; then you would end up with atoms.If you take a substance and could keep cutting it up; then you would end up with atoms.  You can have an atom of gold, lead, platinum, silver, etc.  Water is a molecule, it is made of three atoms: 2 hydrogen atoms and one oxygen atom. Helium Atom

8. Nucleus - Inner part of the Atom  Nucleus mean center. The nucleus of an atom is the center of the atom.The nucleus of an atom is the center of the atom. The nucleus contains two subatomic particles.The nucleus contains two subatomic particles.  Subatomic – “sub” means smaller then, and “atomic” means atom. Protons and Neutrons.Protons and Neutrons.

9. Proton – Positively charged particle.  Protons are particles that have a positive charge.  The amount of protons determines the atomic number of an element on the periodic table.  The periodic table is arranged by protons. The number of protons determines the element.The number of protons determines the element. nitrogen

10. Neutrons are (“neu” ) neutral in charge.  Neutrons a particles without a charge. The are not positive or negative, they are neutral.The are not positive or negative, they are neutral. The proton and neutron weigh the same and together they make up the atomic mass.The proton and neutron weigh the same and together they make up the atomic mass.  The big number on the periodic table. Oxygen 15.99

11. Think for a minute.  If the small number tells you the number of protons.  And the large number tells us the amount of protons and neutrons.  Then could we use these two numbers and find the amount of neutrons? How?How?

12. Answer  Take the atomic mass (mass of the nucleus). For gold it would be 197.For gold it would be 197.  Subtract the atomic number For gold it would be 79.For gold it would be 79.  197 – 79 = 118  There are 118 Neutrons in gold.  In other words in the nucleus in an atom of gold has 197 particles. 118 particles are neutrons, 79 particles are protons.

13. Your Turn  Atomic Mass =  Atomic Number =  Atomic Mass – atomic number = Neutrons.  How many protons in silver?  How many neutrons in silver? Silver 107.868

14. Answer to Your Turn  Atomic Mass = 108  Atomic Number = 47  Atomic Mass – atomic number = Neutrons. 108 – 47 = Neutrons  How many protons in silver? 47  How many neutrons in silver? 61 Silver 107.868

15. Last time, you are on your own!  How many protons?  How many neutrons?  Atomic number = ?  Atomic mass = ? If you can figure out this element then you are a master of the periodic table.

16. Atoms have one type of particle outside the nucleus = Electrons  Electrons are negatively charged particles.  The weigh so much less then a proton that they have no effect on the mass of the element.  Electrons are found in equal amounts to protons. Atoms are electrically neutral.Atoms are electrically neutral.  Electrons are responsible for chemical reactions

17. Think about it.  The amount of electrons always equals the amount of protons.  Gold has 79 protons.  Gold has 79 electrons.  Gold has 118 neutrons.  Gold’s atomic mass = 197  Gold’s atomic number = 79

18. How many electrons?

19. See if you can do it all.  Protons =  Electrons =  Neutrons =  Atomic mass =  Atomic number =

20. Ninja Monkey Street says,  “You need to learn how to read the periodic table or I will monkey foot chop you!!!”