1. Inquiry into Life Twelfth Edition
Lecture PowerPoint to accompany
Inquiry into Life Twelfth Edition
Sylvia S. Mader
Chapter 2
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 2.1 Basic Chemistry
Matter is anything that takes up space and has weight.

3. 2.1 Basic Chemistry Energy is the ability to do work.
Matter is anything that takes up space and has mass.
Matter and Energy can be exchanged, but cannot be destroyed.
All matter, living or nonliving, is made up of elements.

4. 2.1 Basic Chemistry
Elements are substances that cannot be broken down to simpler substances with different properties.

5. Elements that make up the Earth’s crust and its organisms.

6. Elements that make up 95% of living organisms (by weight)
C Carbon

7. Elements that make up 95% of living organisms (by weight)
C Carbon
H Hydrogen

8. Elements that make up 95% of living organisms (by weight)
C Carbon
H Hydrogen
N Nitrogen

9. Elements that make up 95% of living organisms (by weight)
C Carbon
H Hydrogen
N Nitrogen
O Oxygen

10. Elements that make up 95% of living organisms (by weight)
C Carbon
H Hydrogen
N Nitrogen
O Oxygen
P Phosphorus

11. Elements that make up 95% of living organisms (by weight)
C Carbon
H Hydrogen
N Nitrogen
O Oxygen
P Phosphorus
S Sulfur

12. Atomic Structure
Atom: The smallest part of an element that displays the properties of the element.

13. Atom: The smallest part of an element that displays the properties of the element.
Atoms are made up of subatomic particles.

14. Subatomic Particles
Protons (positively charged)

15. Subatomic Particles
Protons (positively charged)
Neutrons (uncharged)

16. Subatomic Particles Electrons (negatively charged)
Protons (positively charged)
Neutrons (uncharged)
Electrons (negatively charged)

17. Helium

18. Atomic Symbol
Atomic
Mass 12 C
Atomic
Number 6
Carbon

19. Atomic Symbol Atomic Mass = Number of Protons + Number of Neutrons
Atomic Number = The Number of Protons
in the Nucleus

20. The Periodic Table

21. Isotopes
C C C*
*radioactive
Atoms of the same element with a differing numbers of neutrons

22. Radiation
As radioactive isotopes decay, energy is released in the form of subatomic particles (radiation).

23. Some Uses of Low Levels of Radiation

24. Some Uses of High Levels of Radiation

25. Electrons

26. Electrons
If an atom is electrically neutral, the number of protons (positively charged) is equal to the number of electrons (negatively charged).

27. Energy Levels (electron shells)

28. Energy Levels (electron shells)
The first shell (closest to the nucleus) can contain two electrons

29. Energy Levels (electron shells)
The first shell (closest to the nucleus) can contain two electrons
Each additional shell can contain eight electrons

30. Energy Levels (electron shells)
The first shell (closest to the nucleus) can contain two electrons
Each additional shell can contain eight electrons
Each lower shell is filled with electrons before the next higher level contains any electrons.

32. Periodic Table (Revisited)
Vertical columns indicate number of electrons in outermost shell I
VIII 1 H
1.008 2 He
4.003 1 II
Horizontal periods indicate total number of electron shells
III IV V VI
VII 3 Li
6.941 4 Be
9.012 5 B
10.81 6 C
12.01 7 N
14.01 8 O
16.00 9 F
19.00 10 Ne
20.18 2 11 Na
22.99 12 Mg
24.31 13 Al
26.98 14 Si
28.09 15 P
30.97 16 S
32.07 17 Cl
35.45 18 Ar
39.95 3 19 K
39.10 20 Ca
40.08 21 Ga
69.72 22 Ge
72.59 23 As
74.92 24 Se
78.96 25 Br
79.90 26 Kr
83.60 4

33. Electrons
Atoms can give up, accept, or share electrons to have eight electrons in the outer shell.

34. 2.2 Elements and Compounds

35. 2.2 Elements and Compounds
Molecules usually form when two or more atoms bond together by forming covalent bonds (example: O2)
A molecule is the smallest particle of matter that can have independent existence: He, Ne, H2, N2, O2, Cl2, CO2, H2O, NH3, CH4

36. 2.2 Elements and Compounds
Molecules form when two or more atoms bond together by forming covalent bonds (example: O2)
Compounds form when two or more different elements bond together
(example: H2O)

37. 2.2 Elements and Compounds
Molecules form when two or more atoms bond together (example: O2)
Compounds form when two or more different elements bond together (H2O)
When a chemical reaction occurs, energy may be given off or absorbed.

38. Ionic Bonding
Ions are charged particles that form when electrons are transferred from one atom to another.

39. Ionic Bonding
Ions are charged particles that form when electrons are transferred from one atom to another.
Ionic compounds are held together by an attraction between oppositely charged ions called an ionic bond.

40. Ionic Bonding

41. Covalent Bonding
In covalent bonds, atoms share electrons allowing each atom to have a completed outer shell.

42. Covalent Bonding
A covalent bond
A double covalent bond

43. Shape of Molecules

44. Nonpolar covalent bonds
If the sharing between two atoms is fairly equal, the covalent bond is described as nonpolar.

45. Polar Covalent Bonds If the sharing between two atoms is unequal,
the covalent bond is described as polar.

46. Hydrogen Bonding
A hydrogen bond occurs between a slightly positive hydrogen atom of one molecule and a slightly negative atom of another molecule, or between atoms of the same molecule.