1. Matter
Chapter 2.1

2. Matter Anything that has mass and occupies space.
Chemistry is the study of matter and how it changes.

6. Pure Substances Uniform and definite composition
Formed and separated chemically
2 types Elements & compounds

7. Pure Substance
Elements – a substance that cannot be broken down into smaller substances.
Atoms – smallest particle that has properties of an element.
Both expressed by symbols

8. Compounds
Compounds – a substance formed when two or more elements chemically combine together.

9. Molecules
The smallest unit of a substance that exhibits all of the properties characteristic of that substance (compound).
Two or more atoms chemically combined

10. Chemical Formulas
Ex. C16H10N2O2

11. Mixtures
A physical combination of more than one substance.
(Two Types)

12. Homogeneous Mixtures Solutions Same throughout (miscible)
ex: flat soda, salt water, black coffee

13. Heterogeneous Mixtures
Not uniformly mixed, different parts
Substances that need to be shaken
ex: noodle soup, granite

15. Classifying Liquid Mixtures:
miscible-dissolve into each other
immiscible-don’t mix into each other. You can see layers
ex: oil and water.

16. Liquids Mix with Gas
Can you think of a very common example???

17. Matter and Energy
2.2

18. Kinetic Theory
All matter is made of atoms and molecules that act like tiny particles.

19. Kinetic Theory
2.These tiny particles are always in motion. The higher the temperature, the faster the particles move.

20. Kinetic Theory
3. At the same temperature, heavier particles move slower than lighter particles.

21. Phases/States of Matter
Gas
liquid
solid
plasma

23. States of Matter - Gases
no definite shape.
no definite volume.
easy to compress.
most random arrangement of particles.
Most spread out.

24. Gases Property of gases is called pressure.
the force exerted per unit area of a surface

25. Liquids Definite volume no definite shape (takes shape of container)
Difficult to compress
disorderly arrangement on particles
Close together

26. Liquids Property of Liquids is called viscosity.
the resistance of a fluid to flow

28. Solids Definite shape Definite volume Difficult to compress
Orderly arrangement of particles close together
Smallest amount of movement of particles.

29. Energy The ability to change state or move matter.
Changing state does not change composition of the substance

31. Changes of State
solid
liquid
gas

32. Law of conservation of matter (mass)
Matter (mass) cannot be created or destroyed.
It only changes its state or rearranges its atoms.

33. Law of conservation of energy
Energy cannot be created or destroyed.
It converts from one form to another during chemical or physical changes.

34. Properties of Matter
2.3

35. Physical Property
A characteristic of a substance that can be observed or measured without changing the composition of the substance.

36. Physical Property
Melting and freezing points.
Solubility
Dissolving of a solid into a liquid.
Density

37. Why do some things float while others sink?

38. Density mass/volume (D=m/V) UNITS: mass – (g) Volume – (mL) or (cm3)
density – (g/mL) or (g/cm3)

39. Density
Buoyancy-
The force with which a more dense fluid pushes a less dense substance upward.
ex. floating ice.

40. Example
An unknown metal is measured to be 36 grams. What is it’s density if it has a volume of 15.5 cm3?
D=m/v d= 36 g/ 15.5 cm3
D = g/cm3
Last point is sig. figs g/cm3 +1 +1 +1

42. Chemical Properties
The way a substance reacts with others to form new substances with different properties.

43. Chemical Properties
Flamability
Reactivity
corrosion

48. Physical Changes
A change in the physical form or properties of a substance that occurs without a change in composition.

49. Chemical Change
A change that occurs when a substance changes composition by forming one or more new substances.

50. Chemical Change 4 signs: Evolution heat or light Color change
Formation of gas
Formation of a precipitate (solid residue)