Classifying Matter: Elements, Compounds, and Mixtures

1. Classifying Matter:Elements, Compounds, and Mixtures

2. What is Matter? • Anything that has mass and takes up space (volume) • What is the only thing that is NOT matter? • All matter is made up of particles: • Atoms • Molecules ENERGY

3. What makes matter? • All matter is made up of tiny particles called atoms • Atoms are considered the building blocks of matter • They are the smallest form of the simplest substances that maintain the properties • Made up of 3 subatomic particles • Protons • Neutrons • Electrons

4. Atoms Nucleus • Atoms have a center nucleus • Made up of protons and neutrons • Around the nucleus is the electron cloud • Contains electrons • Exist in orbitals and energy levels Electron Cloud

5. Protons • They are positively charged. • Are located in the nucleus. • In this picture, the protons are the yellow pieces in the center of the atom.

6. Neutrons • Neutrons are neither positive nor negative. • Same mass as a proton • Neutrons are in the nucleus of an atom. • In this picture, neutrons are the blue pieces in the center of the atom.

7. Electrons • Electrons orbit around an atom. • They have a negative charge. • They have almost no mass • They move quickly and continuously.

8. Molecules • When two or more atoms combine chemically, they form a chemical “bond” • The result is called a molecule • A molecule is the smallest particle of a compound • This is a picture of a water molecule. It is two parts hydrogen and one part oxygen.

10. Pure Substances • A sample of matter that has definite chemical and physical properties. • It is the same throughout • Pure Substances are either: • Elements • Compounds

11. Elements • An element is a substance made up of only one kind of atom. • Elements are the simplest substances. • They can’t be separated into any simpler substance by physical or chemical means • Elements make up all other substances on the earth.

12. Elements • Elements are represented by chemical symbols • Found on the Periodic Table of Elements

13. Compounds • It is made from two or more elements chemically combined. • A compound is made up of all the same molecule throughout • Made of elements in a specific ratio that is always the same • Can only be separated by chemical means, not physically

14. Compounds • Compounds are represented by chemical formulas • Formulas show the number of atoms of each element bonded together in the molecule.

15. Chemical Formulas • Letter(s) or symbol tell you the elements in the compound • Small numbers after the element are called subscripts. They tell the number of atoms of that element that are present • Large numbers out in front are called coefficients. They tell the number of molecules present

16. Chemical Formulas C16H10N2O2 4CO2

17. Mixtures • A combination of two or more pure substances that are not chemically combined. • No chemical change takes place when combined • Substances are physically combined only, not chemically • Each item retains its properties in the mixture • They can be separated by physical means • By hand • Boiling • Sifting • Etc.

18. Compare and Review

19. Compare and Review

20. Can you identify the following? You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture. Review: • An element contains just one type of atom. • A compound contains two or more different atoms joined together. • A mixture contains two or more different substances that are only physically joined together, not chemically. • A mixture can contain both elements and compounds.

21. Element, Compound, or Mixture? Rocks

22. Element, Compound, or Mixture? Rocks

23. Element, Compound, or Mixture? Copper

24. Element, Compound, or Mixture? Copper Cu

25. Element, Compound, or Mixture? Jelly Beans

26. Element, Compound, or Mixture? Jelly Beans

27. Element, Compound, or Mixture? Table Sugar

28. Element, Compound, or Mixture? Table Sugar C12H22O11

29. Element, Compound, or Mixture? Diamond

30. Element, Compound, or Mixture? Diamond C

31. Element, Compound, or Mixture? Tea

32. Element, Compound, or Mixture? Tea

33. Element, Compound, or Mixture? Salt

34. Element, Compound, or Mixture? NaCl Salt

35. Element, Compound, or Mixture? Neon Gas

36. Element, Compound, or Mixture? Ne Neon Gas

37. Element, Compound, or Mixture? Salad

38. Element, Compound, or Mixture? Salad

39. Element, Compound, or Mixture? Pure Water

40. Element, Compound, or Mixture? Pure Water H2O

41. Element, Compound, or Mixture? Aluminum

42. Element, Compound, or Mixture? Aluminum Al

43. Element, Compound, or Mixture? Lemonade

44. Element, Compound, or Mixture? Lemonade

45. Element, Compound, or Mixture? Silver

46. Element, Compound, or Mixture? Silver Ag

47. Element, Compound, or Mixture? Sand

48. Element, Compound, or Mixture? Sand

49. Heterogeneous vs Homogeneous Mixtures

50. Definitions: The prefix “homo” – indicate sameness Homogeneous – A homogeneous mixture has the same uniform appearance throughout. Many homogeneous mixtures are commonly referred to as solutions.