Matter

1. Matter Chapter 2

2. Definition • Matter is anything that has mass and takes up space. • Mass is a measure of the amount of matter. • Volume is a measure of the amount of space.

3. Types of Matter • An element is a substance that cannot be separated or broken down into simpler substances by chemical means. • An atom is the smallest unit of an element that maintains the properties of that element.

4. Combinations of Matter • A compound is a substance made up of atoms of two or more different elements joined by chemical bonds. • A molecule is the smallest unit of a substance that keeps all of the physical and chemical properties of that substance.

5. Chemical Formulas • Chemical formula shows how many atoms of each element are in a unit of a substance. • Chemical symbols represent the element. • Subscripts indicate how many atoms of each element are in one molecule of the compound.

6. Mixtures • Pure substances is matter that has a fixed composition and definite properties. • A mixture is a combination of two or more substances that are not chemically combined.

7. Types of Mixtures • Heterogeneous mixture aren’t mixed uniformly and are not evenly distributed. • Homogeneous mixture are evenly distributed and the mixture is the same throughout.

8. What is used to define matter? • mass • volume • Both mass and volume. • Neither mass nor volume. 0 of 28 10

9. What is the smallest part of an element? • atom • compound • mixture • molecule 0 of 28 10

10. What do we call a physical combination of two or more substances? • compound • element • mixture • molecule 0 of 28 10

11. What is milk an example of? • compound • Heterogeneous mixture • Homogeneous mixture • element 0 of 28 10

12. Physical Properties • Physical Properties are characteristics of a substance that does not involve a chemical change, such as density, color or hardness. • Examples are melting point, boiling point, strength, hardness, conductivity, magnetism, heat.

13. Chemical Properties • Chemical properties are characteristics of matter that describes a substance's ability to participate in chemical reactions. • Examples are reactivity with oxygen, acid, water, or other substances; flammability.

14. Physical Changes • Physical changes are changes of matter from one form to another without a change in chemical properties. • Examples are cutting, dissolving, mixing, melting, evaporating, subliming.

15. Chemical Changes • Chemical changes are changes that occur when a substance changes composition by forming one or more new substances. • Examples are burning, rusting, and ripening of fruit.

16. Triple Point of Carbon Dioxide • Under certain conditions, you can see dry ice as a solid, liquid and gas all at the same time. • Dry ice under pressure will exhibit all three states of matter. • Under normal conditions, dry ice will sublime from a solid to a gas.

17. Kinetic Theory • All matter is made of atoms and molecules that act like tiny particles. • These tiny particles are always in motion. The higher the temperature of the substance, the faster the particles move. • At the same temperature, more massive particles move slower than less massive particles.

18. Different States of Matter • Solids • Definite volume. • Definite shape. • Low energy, molecules close together. • Liquids • Definite volume. • No definite shape. • More energy, molecules farther apart.

19. Different States of Matter • Gases • No definite volume. • No definite shape. • Lots of energy, molecules are very far apart. • Plasma • No definite shape. • Particles have been broken apart.

20. Energy in States of Matter • Energy is the ability to change or move matter. • Thermal energy is the total kinetic energy of the particles that make up an object.

21. Change in States of Matter • Evaporation is the change of a substance from a liquid to a gas. • Boiling point is the evaporation of a liquid at a certain temperature. • Sublimation is the process by which a solid turns directly into a gas.

22. Changes is States of Matter • Condensation is the changes of state from a gas to a liquid. • Melting is the process of a solid changing into a liquid. • Freezing is the reverse of melting.

23. Conservation of Mass & Energy • The law of conservation of mass states that mass cannot be created or destroyed. • The law of conservation of energy states that energy cannot be created or destroyed.

24. Fluids • Buoyant force is the upward force that fluids exert on matter. • All fluids exert pressure, which is the amount of force exerted on a given area.

25. Archimedes’ Principle • Archimedes Principle states that the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid that the object displaces.

26. Fluid & Pressure • Pressure is the amount of force applied over an area. • Pressure=force/area

27. Pascal’s Principle • Pascal’s principle states that a change in pressure at any point in an enclosed fluid will be transmitted equally to all part of the fluid.

28. Fluids in motion • Viscosity is a liquid’s resistance to flow. • Bernoulli’s principle states that as the speed of a moving fluid increases, the pressure of the moving fluid decreases.

29. Properties of Gases • Gases have no definite shape or volume, and they expand to completely fill their container. • Gas particles move rapidly in all directions. • Gases are fluids.

30. Properties of Gases • Gases have no definite shape or volume, and they expand to completely fill their container. • Gas particles move rapidly in all directions. • Gases are fluids.

31. Properties of Gases • Gas molecules are in constant motion, and they frequently collide with one another and with the walls of their container. • Gases have a very low density because their particles are so far apart. Because of this property, gases are used to inflate tires and balloons.

32. Properties of Gases • Gases are compressible. • Gases spread out easily and mix with one another. Unlike solids and liquids, gases are mostly empty space.

33. Gas Laws • Gas laws explain the relationship between volume, temperature and pressure of gases. • Different Laws: • Boyle’s Law • Charles’ Law • Gay-Lussac’s Law

34. Boyle’s Law • Boyle’s Law states that for a fixed amount of gas at a constant temperature, the volume of a gas increases as its pressure decreases. • P1V1=P2V2

35. Charles’ Law • Charles Law states that for a fixed amount of gas at a constant pressure, the volume of the gas increases as its temperature increases. • K=V/T

36. Gay-Lussac’s Law • Gay-Lussac’s Law states that the pressure of a gas increases as the temperature increases if the volume of the gas does not change.

37. Atoms and the Periodic Table Chapter 4

38. Atomic Structure • Atoms are the simplest unit of a substance that still maintain the properties of the substance. • John Dalton proposed that atoms could not be divided. • Dalton also stated that atoms of different elements could join to form compounds.

39. Parts of an Atom • Atoms are composed of subatomic particles. • Protons and neutrons are found in the nucleus of the atom. • Electrons are found in orbitals around the nucleus of the atom.

40. Protons • Protons have a positive charge. • Protons have the mass of one amu (atomic mass unit). • The number of protons in an atom is characteristic of that element. • Each element has different number of protons.

41. Neutrons • Neutrons have no charge. • Neutrons have the mass of one amu. • Neutrons add to the mass of an atom. • Atoms of the same element with different number of neutrons have different masses (isotopes).

42. Electrons • Electrons have a negative charge. • Electrons have the mass of 1/2000 the mass of a proton. • The mass of an electron is insignificant. • The outer most electrons determine how elements combined in chemical compounds.

43. Quarks • A quark (IPA: /kwɔrk/) is a generic type of physical particle that forms one of the two basic constituents of matter, the other being the lepton. • Various species of quarks combine in specific ways to form protons and neutrons, in each case taking exactly three quarks to make the composite particle in question.

44. Models of Atoms • Niels Bohr suggested that electrons in an atom move in set paths around the nucleus. • Electrons can only be in certain energy levels. • Number of electrons=2n2

45. Electron Cloud Model • This model suggest that electrons orbit the nucleus in a cloud. • The regions in an atom where electrons are likely to be found are called orbitals. • The four different kinds of orbitals are the s, p, d and f orbitals.

46. Valence Electrons • An electron in the outermost energy level of an atom is called a valence electron. • Valence electrons determine an atom’s chemical properties and its ability to form bonds.

47. Periodic Table • The Periodic Law states that when elements are arranged this way, similarities in their properties will occur in a regular pattern.

48. Structure of the Periodic Table • Horizontal rows in the periodic table are called periods. • Atoms of elements in the same group, or column, have the same number of valence electrons, so these elements have similar properties.

49. Ions Formation • Atoms that gain or lose electrons form ions. • Elements that lose electrons have a positive charge (cation). • Elements that gain electrons have a negative charge (anion).

50. Periodic Information • The atomic number is the number of protons in an element. • The mass number of an atom equals the number of protons plus the number of neutrons.