2. The Atoms Family Atoms are the smallest form of elements

3. Matter Anything that has mass and takes up space (has volume) Made up of different kinds of atoms Includes all things that can be seen, tasted, smelled, or touched Does not include heat, sound, or light

4. In science, anything that has mass and takes up space is called matter Everything in the universe is made of matter A really loooooong time ago, the Greeks concluded that matter could be broken down into particles too small to be seen. They called these particlesatoms

5. So, what’s an atom? An atom is the smallest piece that matter can be broken down to Okay, but I’ve never seen an atom... Where are they?

6. Atoms are EVERYWHERE!! Atoms are in... hair desks dirt chocolate cheese CDs air And even underwear boogers cars hot dogs plants

7. Pop Quiz Question #1 What are the three states of matter? A.solid, water, boiling B.Water, ice, steam C.Solid, liquid, gas D.earth, rain, air

8. What do atoms look like? There is no "atomic microscope" which would allow one to look inside an atom and say, "Aha! There's 7 blue protons, 6 white neutrons, and 7 red electrons." The way the structure of the atom was devised was through a long series of experiments Scientists have developed models...

9. Models In the case of atoms, scientists use large models to explain something that is very small Models of the atom were used to explain data or facts that were gathered experimentally. So, these models are also theories

10. Early Models of the Atom Democritus Universe was made of empty space and tiny bits of stuff Called these tiny bits of stuff atomos Atoms could not be divided

11. Early Models of the Atom Dalton All elements are composed of indivisible particles. Atoms of the same element are the same Atoms of different elements are different. Compounds consisted of atoms of different elements combined together

12. Early Models of the Atom Thompson Plum pudding model Atom made of a positively charged material with the negatively charged electrons scattered through it.

13. Early Models of the Atom Rutherford Mostly empty space Small, positive nucleus Contained protons Negative electrons scattered around the outside

14. Early Models of the Atom Bohr Electrons move in definite orbits around the nucleus Solar system model

15. Modern Model of the Atom The electron cloud Sometimes called the wave model Spherical cloud of varying density Varying density shows where an electron is more or less likely to be

16. Atomic Structure Electrons –Size = Tiny, very light particles –Charge = negative electrical charge (-) –Location = Move around the outside of the nucleus –Number = Same as Protons (if atom is neutral) –Purpose: Does the Work Bonding Chemical Reactions

17. Atomic Structure Protons –Size = Much larger and heavier than electrons –Charge = positive charge (+) –Location = in nucleus of the atom –Number = Same as Atomic Number –Purpose: Keeps the electrons around

18. Atomic Structure Neutrons –Size = Bigger than protons –Charge = no electrical charge (0) –Location = nucleus of the atom –Number = Atomic Mass – Atomic Number –Purpose: Keeps the protons together

19. Protons and Neutrons Protons and neutrons are responsible for most of the mass of an atom. If the proton and neutron each had the mass of a hippo, the electron would have less mass than an owl. Protons and neutrons are located in the of the atom nucleus

20. Pop Quiz Question #2 Do neutrons have a charge? A.Yes, they’re positive. B.Yes, they’re negative. C.Yes, they’re neutral. D.No, they’re neutral.

21. Pop Quiz Question #3 What are the three parts of an atom? A.Solid, liquid, gas B.Proton, neutron, electron C.Atom, cell, virus D.Positive, negative, neutral

22. Pop Quiz Question #4 Where are protons and neutrons located in the atom? A.The left B.The right C.Nucleus Arcade D.Nucleus

23. Electrons Electrons travel really fast around the nucleus in electron orbits or shells Only electrons are located on the first shell, can fit onto the second shell, fit onto the third shell, and fit onto the fourth shell. 2 18 32 8

24. Bohr’s Model of the Atom electron proton neutron shell

25. Electron Cloud Model proton electron cloud

26. Elements An is any piece of matter that consists of only atom. element one There are over 100 elements known to man Each element has a name and a symbol

27. Describing Atoms Each element is identified by itsatomic number The atomic number tells how many are in the nucleus and how many are in the shells protons electrons The total number of protons and neutrons in the nucleus is called the atomic mass number A neutral atom has the same amount of protons and electrons.

28. Atomic Math To determine the amount of neutrons for each element, the from the subtractatomic number atomic mass number How many protons does zinc have? How many electrons does zinc have How many neutrons does zinc have? 30 35

29. Pop Quiz Question #5 What information does the atomic number provide? A.The number of protons and electrons B.The number of protons and neutrons C.The number of neutrons and electrons D.Only the number of protons

30. Pop Quiz Question #6 An atom is stable when there are the same number of protons as electrons. What would be the charge of an oxygen atom that “lost” two electrons? A.Positive B.Negative C.Neutral

31. Ions An atom that carries an electrical charge is called an ion Cation –If the atom loses electrons, the atom becomes positively charged (because the number of positively charged protons will be more the number of electrons) Anion –If an atom gains electrons, the atom becomes negatively charged (more negative charges than positive charges)

32. Ions The number of protons does not change in an ion The number of neutrons does not change in an ions So, both the atomic number and the atomic mass remain the same.

33. Ions Sodium has lost an electron. Now it has one more proton than electron. One more proton means one more positive charge. This makes the total charge of the atom POSITIVE. Chlorine has gained an electron. Now it has one less proton than electron. One less proton means one less positive charge. This makes the total charge of the atom NEGATIVE.

34. Isotopes The number of protons for a given atom never changes. The number of neutrons can change. Atoms with different numbers of neutrons are called isotopes

35. Drawing Isotopes

36. How to Write an isotope Name of element – Mass Number (Protons + Neutrons)  Hydrogen – 1 (has one particle in the nucleus *the one particle in the nucleus is a proton  Hydrogen – 2 (has 2 particles in the nucleus) *Subtract the atomic number from the new atomic mass to get the new number of neutrons)  Hydrogen – 3 (has three particles in the nucleus) *Only one particle is a proton, the others must be nutrons)

37. Pop Quiz Question # 7 How would you write an isotope for carbon that has 2 extra neutrons? A.Carbon-2 B.Carbon-12 C.Carbon-14 D.Carbon-16