1. The chemical context of life

2. Key concepts
Matter consists of chemical elements in pure form and in combinations called compounds
An element’s properties depend on the structure of its atoms
The formation and function of molecules depend on chemical bonding between atoms
Chemical reactions make and break chemical bonds

3. Matter consists of chemical elements in pure form and combinations called compounds

4. Matter consists of chemical elements in pure form and combinations called compounds
What is matter?

5. Matter consists of chemical elements in pure form and combinations called compounds
Something that has mass and occupies space
Matter consists of atoms

6. Matter consists of chemical elements in pure form and combinations called compounds
Something that has mass and occupies space
Matter consists of atoms
What are atoms?

7. Matter consists of chemical elements in pure form and combinations called compounds
Something that has mass and occupies space
Matter consists of atoms
Atoms are the fundamental building block of all substances.
The smallest unit of matter that retains the properties of an element

8. Matter consists of chemical elements in pure form and combinations called compounds
Something that has mass and occupies space
Matter consists of atoms
Atoms are the fundamental building block of all substances.
The smallest unit of matter that retains the properties of an element.
What is an element?

9. Matter consists of chemical elements in pure form and combinations called compounds
Something that has mass and occupies space
Matter consists of atoms
Atoms are the fundamental building block of all substances.
The smallest unit of matter that retains the properties of an element.
An element is a substance that cannot be broken down into other substances by chemical reaction.

10. Matter consists of chemical elements in pure form and combinations called compounds
Something that has mass and occupies space
Matter consists of atoms
Atoms are the fundamental building block of all substances.
The smallest unit of matter that retains the properties of an element.
Why?
An element is a substance that cannot be broken down into other substances by chemical reaction.

11. Matter consists of chemical elements in pure form and combinations called compounds
Each element is composed on a single type of atom
Compounds are made of more than one element in a fixed ratio
hydrogen and oxygen
gold
sodium and chloride

12. Matter consists of chemical elements in pure form and combinations called compounds
Whether they are in compounds or in pure form, there are relatively few elements in living organisms

13. Matter consists of chemical elements in pure form and combinations called compounds

14. An element’s properties depend on the structure of its atoms

15. An element’s properties depend on the structure of its atoms
What do we mean by properties?

16. An element’s properties depend on the structure of its atoms
Properties-melting point, bonding, and density are common examples.

17. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Nucleus

18. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons
Nucleus
Contains:
Protons
Neutrons

19. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons He
Nucleus
Contains:
Protons
Neutrons 2
All atoms of the same element will have the same number of protons (Atomic number)

21. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons He
Nucleus
Contains:
Protons
Neutrons 2
All atoms of the same element will have the same number of protons (Atomic number)
The number of neutrons typically equals the number of protons

22. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons He 4
Nucleus
Contains:
Protons
Neutrons 2
All atoms of the same element will have the same number of protons (Atomic number)
The number of neutrons typically equals the number of protons
Mass number is the number of protons + number of neutrons

24. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons He 4
Nucleus
Contains:
Protons
Neutrons 2
All atoms of the same element will have the same number of protons (Atomic number)
The number of neutrons typically equals the number of protons
Mass number is the number of protons + number of neutrons
The number of electrons typically equals the number of protons

25. What is the atomic number of Aluminum?

26. How many protons does Lithium have?

27. What is the mass number of Chloride?

28. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons He 3
Nucleus
Contains:
Protons
Neutrons 2
All atoms of the same element will have the same number of protons (Atomic number)
The number of neutrons typically equals the number of protons (not for isotopes)
Mass number is the number of protons + number of neutrons
The number of electrons typically equals the number of protons

29. An element’s properties depend on the structure of its atoms
Atomic structure
Electron cloud
Contains:
Electrons He + 4
Nucleus
Contains:
Protons
Neutrons 2
All atoms of the same element will have the same number of protons (Atomic number)
The number of neutrons typically equals the number of protons (not for isotopes)
Mass number is the number of protons + number of neutrons
The number of electrons typically equals the number of protons (not for ions)

30. An element’s properties depend on the structure of its atoms
Atomic structure
Focusing on electrons- Atomic nuclei don’t interact, electrons do
Electrons vary in the amount of energy they possess because of their position relative to the nucleus.
They are attracted to the nucleus
It takes work (energy) to be far from it
They reside in energy levels (shells)

31. An element’s properties depend on the structure of its atoms
Atomic structure
Focusing on electrons- Atomic nuclei don’t interact, electrons do

32. An element’s properties depend on the structure of its atoms
Atomic structure
Focusing on electrons-The chemical behavior of an atom is determined by the distribution of its electrons
Hydrogen 1H
Lithium
3Li
Beryllium
4Be
Boron 5B
Carbon 6C
Nitrogen 7N
Oxygen 8O
Fluorine 9F
Neon
10Ne
Helium
2He
First
shell
Second
Third
Sodium
11Na
Magnesium
12Mg
Aluminum
13Al
Silicon
14Si
Phosphorus
15P
Sulfur
16S
Chlorine
17Cl
Argon
18Ar

33. An element’s properties depend on the structure of its atoms

34. The formation and function of molecules depend on chemical bonding between atoms

35. The formation and function of molecules depend on chemical bonding between atoms
Different types of bonds
Covalent bonds (strongest) - involves the sharing of electrons (i.e. H2)
Electrons may be spread equally across the bond (non-polar bond)
Electrons may not be spread equally across the bond (polar bond)

36. The formation and function of molecules depend on chemical bonding between atoms
Natural
endorphin
Morphine
Endorphin
receptors
Brain cell
(b)
Binding to endorphin receptors

37. The formation and function of molecules depend on chemical bonding between atoms
Different types of bonds
Covalent bonds (strongest) - involves the sharing of electrons (i.e. H2)
Electrons may be spread equally across the bond (non-polar bond)
Electrons may not be spread equally across the bond (polar bond)
Ionic bonds- Charge-charge interactions
An interaction between a positive and negative charge
Can form after one atoms strips a valence electron from another (ie. NaCl)
Forms salts

38. The formation and function of molecules depend on chemical bonding between atoms
Ionic bond
Electron
transfer
forms ions Na
Sodium atom Cl
Chlorine atom
Na+
Sodium ion
(a cation)
Cl–
Chloride ion
(an anion)

39. Which elements will most likely form an ionic bond?
a. Li and F
b. C and O
c. N and O
d. Si and Cl
e. H and H

40. The formation and function of molecules depend on chemical bonding between atoms
Different types of bonds (weak)
Hydrogen bonds- involve polar covalent bonds, form when a hydrogen atom is bonded to a more electronegative atom

41. The formation and function of molecules depend on chemical bonding between atoms
Different types of bonds (weak)
Hydrogen bonds- involve polar covalent bonds, form when a hydrogen atom is bonded to a more electronegative atom
This impacts the properties of water!

42. The formation and function of molecules depend on chemical bonding between atoms
Different types of bonds (weak)
Hydrogen bonds- involve polar covalent bonds, form when a hydrogen atom is bonded to a more electronegative atom
Vander Waals interactions- involve non-polar covalent bonds, occur when an electron accumulation arises by chance

43. The formation and function of molecules depend on chemical bonding between atoms

44. Chemical reactions make and break chemical bonds

45. Chemical reactions make and break chemical bonds
Chemical reaction- making a breaking of chemical bonds leading to changes in the composition of matter

46. Chemical reactions make and break chemical bonds
Chemical reaction- making a breaking of chemical bonds leading to changes in the composition of matter
6 CO2 + 6 H2O C6H12O6 + 6O2

47. Chemical reactions make and break chemical bonds

48. Key concepts
Matter consists of chemical elements in pure form and in combinations called compounds
An element’s properties depend on the structure of its atoms
The formation and function of molecules depend on chemical bonding between atoms
Chemical reactions make and break chemical bonds