Atoms and Elements and Compounds: Are they Related?

1. Atoms and Elements and Compounds: Are they Related? BGJHS Science 7th Grade

2. Matter • Matter is anything that has mass and volume (takes up space).

3. ATOMS • ALL MATTER IS MADE OF ATOMS • Definition: ATOMS ARE THE SMALLEST PIECE OF MATTER and CANNOT BE BROKEN DOWN INTO A SIMPLER SUBSTANCE.

4. ATOMS HAVE 3 BASIC PARTS (Subatomic Particles) • PROTONS • NEUTRONS • ELECTRONS

5. PROTONS(POSITIVE CHARGE) • ARE FOUND IN THE NUCLEUS AND MAKE UP MOST OF THE MASS OF THE ATOM. • VERY IMPORTANT!!! The number of protons an atom has tells you what kind of atom it is!!!!

6. NEUTRONS(NO CHARGE) • ARE FOUND IN THE NUCLEUS • MAKE UP PART OF THE MASS OF THE ATOM

7. Isotopes • Atoms of the same element that have a different number of neutrons. EX: Carbon Carbon-12 Carbon-13 Carbon-14

8. Isotopes & Radioactive Decay • Atoms are most stable when they have the same number of Pro/Neu in the nucleus… • So, having more neutrons causes atom to be unstable & “repulsion” builds up. • Nucleus becomes more stable when the extra particles are released & energy is given off. • RD is the release of extra nuclear particles & energy.

9. ELECTRONS(NEGATIVE CHARGE - ) • FOUND IN THE ELECTRON SHELL (cloud) ORBITING THE NUCLEUS. • TAKES UP MOST OF THE SPACE IN AN ATOM.

10. Valence Electrons • Outermost electron(s) in the cloud/shell • 8 is the magic number!!!!!! (octet rule)

11. Ions • Atom where the total number of electrons does not equal the total number of protons (atom will have a pos or neg charge) • Cation= pos (loss of e-) • Anion=neg (gain of e-) • EX: Fe2+, Al3+, O2-

12. How to Find: • # of Protons • The atomic number IS the number of protons • Atomic number is located on the periodic table

13. # of Protons • If the atomic # is 7, what is the # of protons? • If the atomic # is 15, what is the # of protons? • If an atom has 22 protons, what is its atomic #. • How many protons does Oxygen have? What is Oxygen’s atomic #? • Neon has 10 protons. What is its atomic #? • If an atom has 35 protons, what is the name of the atom?

14. How to Find: • # of Neutrons • You can find the number of neutrons by subtracting the atomic mass from the # of protons (atomic number). atomic mass - # of protons = # of neutrons

15. # of Neutrons • If an atom’s mass is 9amu and has 4 protons, how many neutrons does it have? • If an atom’s mass is 14amu and has atomic number of 7, how many neutrons does it have? • How many neutrons does aluminum have? • How many neutrons does calcium have? • An atom has a mass of 28amu and 14 neutrons, what type of atom is it?

16. # of Neutrons • If an atom of germanium has 41 neutrons and 32 protons, what is its atomic mass? • Nickel has an atomic number of 28 and has 31 neutrons, what is its mass?

17. Isotopes & Mass Number • If we have a different number of neutrons, will the mass be affected? • EX: since C-14 has 8 neutrons, the mass number is 14amu instead of 12amu (C-12).

18. Isotopes • Atoms of the same element that have a different number of neutrons. EX: Carbon Carbon-12 Carbon-13 Carbon-14

19. How to Find • # of Electrons • The # of electrons IS EQUAL to the # of protons

21. # of Electrons • If Helium has 2 protons, how many electrons does it have? • If the atomic number of magnesium is 12, how many electrons does it have? • If an atom has 21 electrons, what type of atom is it?

22. How to Find: • Atomic Mass • You can find the atomic mass by adding the # of protons and the # of neutrons • # of protons + # of neutrons = atomic mass

23. Putting it all together…

24. Discovery of the Atom (pg. 80) By the early 1800’s, John Dalton proposed that all substances are made up of atoms. In 1898, J.J. Thomson, proposed that atoms are made up of smaller parts. In 1911, Ernest Rutherford, proposed that atoms have electrons and a positively charged nucleus.

25. Dalton’s Atomic Theory • All matter is made of atoms. Atoms are indivisible and indestructible. • 2) All atoms of a given element are identical in mass and properties • 3) Compounds are formed by a combination of two or more different kinds of atoms. • 4)A chemical reaction is a rearrangement of atoms.

26. Niels Bohr’s model of the atom that shows the electrons revolving around the nucleus in circular paths called orbits.

27. Current Atomic Theory: Electron Cloud Model Electrons travel in regions of various thicknesses called clouds (shells).

28. Label the atom below on your packet! What type of atom is this? How do you know?

29. PIN THE NUCLEUS ON THE ATOM

30. Elemental Candy

32. ELEMENTSARE PURE SUBSTANCES MADE OF TWO OR MORE OF THE SAME KIND OF ATOM. • SOME COMMON ELEMENTS • HYDROGEN (H), HELIUM (He), OXYGEN (0), • Notice that the first letter is capital and the next letter is lower case.

33. ELEMENTS • ARE THE BUILDING BLOCKS OF MATTER. • CANNOT BE BROKEN DOWN INTO A SIMPLER SUBSTANCE. • HAVE THEIR OWN UNIQUE SET OF PROPERTIES THAT NO OTHER ELEMENT HAS.

34. ELEMENTS • There are 92 naturally occurring elements on the periodic table. This means they are in nature and not made in a laboratory by scientists. • As of the year 2015 there are 118 known elements but there are gaps.

35. Elements • Most Elements • are rarely found alone in nature • react with water or oxygen • easily undergo a chemical change

36. Atoms and Elements Activity • As a group, look at the food labels on the items at your table. Make a list of the items in the left hand side column and in the right hand side column make a list of any elements found in that substance. • You may use your periodic table to help you identify the elements.

37. The food item would be: Cooked Ham What are the elements that are found on this food label?

38. QUESTIONS???? • What are the most commonly occurring elements in the food labels? • What items seemed to have the most amount of elements in them? • Can you predict what that means about the food item? • Why do you think the baby formula has such a variety of elements? • Can you predict what the other items on the food label are if they are not elements?

39. PERIODIC PATTERNS

40. Periodic Table • The periodic table is an organized table of each element. • Each box gives information about each type of element found on Earth.

41. Dmitri Mendeleev (1869) In 1869 Mendeleev and Lothar Meyer (Germany) published nearly identical classification schemes for elements known to date. The periodic table is base on the similarity of properties and reactivities exhibited by certain elements. Later, Henri Moseley ( England,1887-1915) established that each elements has a unique atomic number, which is how the current periodic table is organized. http://www.chem.msu.su/eng/misc/mendeleev/welcome.html

42. ELEMENTS ARE ORGANIZED IN THE PERIODIC TABLE ACCORDING TO INCREASING ATOMIC NUMBER.

43. ELEMENTS ARE ORGANIZED IN THE PERIODIC TABLE OF ELEMENTS ACCORDING TO THEIR SIMILARCHARACTERISTICS

44. Iron- Fe (Ferrum) Lead- Pb (Plumbum) • Elements & their symbols • SOME COMMON ELEMENTS • HYDROGEN (H), HELIUM (He), OXYGEN (0), • Notice that the first letter is capital and the next letter is lower case. Gold- Au (Aurum)

45. Element Info in Each Box Atomic Mass Atomic Number Symbol Name

46. Arrangement of the Periodic table Periods– Rows are called periods. The elements in these rows change conductivity and number of electrons as you move across the table. Groups – Columns are called groups or families. These elements have the same properties because of the number of electrons.

47. How is the Periodic Table Organized? Periods Even though they skip some squares in between, all of the rows go left to right. When you look at a periodic table, each of the rows is considered to be a different period

48. There are 7 periods. Each period represents the number of electron shells. • Elements in period 1 have 1 electron shell. • Elements in period 5 will have 5 electron shells.

49. Across the Periodic Table • Periods: Are arranged horizontally across the periodic table (rows 1-7) • These elements have the same number of valence shells. 2nd Period 6th Period

50. When a column goes from top to bottom, it's called a group or family. Groups Groups are often called families because these elements seem to be related. **Elements in the same group show similarities in their chemical and physical properties.