1. Chemistry for Living Things

2. Composition of Matter
Matter – anything that takes up, or occupies space….and has mass!
Mass – amount of matter in an object
ARE Mass and Weight the same????

3. Most Common Elements in Living Organisms
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
90% of living things are made of these 4 Elements

4. What Are Atoms? Smallest particles that keep properties of an element.
Two parts: Energy rings and nucleus (center)
Made up of 3 subatomic particles:
Protons (+)  found in the nucleus
Electrons (-)  found in the energy rings around the nucleus, repel one another, attracted to the protons
Neutrons (no charge)  found in nucleus
Must have equal number of protons and electrons
Must remain electrically stable

5. C 12.011 6 atomic number # of protons or electrons element symbol
and name
atomic mass
# of protons + # of neutrons
12.011
Round to make it a whole number

6. Na K Cl 1) 2) 3) ------Atomic # ------Atomic # ------Atomic # 11
Element
Atomic mass aka Mass # 11
Sodium
22.93~ 23 1) Na
How many Electrons? How many Protons? How many neutrons?
= N + 11
N= 12
------Atomic #
Element
Atomic mass aka Mass # 19
Potassium
39.098~ 39 K 2)
How many Electrons? How many Protons? How many neutrons?
= N + 19
N= 20
------Atomic #
Element
Atomic mass aka Mass # 3) 17
Chlorine
35.453~ 35 Cl
How many Electrons? How many Protons? How many neutrons?
=N+17
N=18

7. Energy Levels – what is the max # electrons in each level?
An element is stable if energy level is completely filled with electrons…it is happy….if not completely filled it is mad and will want to react
8 is the happy number, except for hydrogen and helium which want 2
If not 8, considered unstable and will react 2 8 8

8. BOHR MODEL PEN write down the numbers of each
Draw nucleus with the P and N
Draw Energy levels around nucleus until you used all your electrons…
remember 2, 8, 8

9. Show a Bohr Model for:
Carbon (#6, mass12)
Sodium (#11, mass 22.9)
Oxygen (#8, mass 15.99)

10. F Lewis Dot Diagrams ___P ___N
Represent the element by the chemical symbol and a “dot” for each valence electron. F 9e 9 F 19 9
___P
___N 10
electron
Symbol for fluorine

11. OPEN NOTES QUIZ!!!
Elements
1)___________ are substances that cannot be broken down into simpler substances.
2) Atoms are composed of _______, _______, & ________.
3) Atoms achieve stability when their ________energy level is filled with ______ electrons.
4) A _____________ bond is formed when two atoms share electrons.
5) An __________bond is formed when one atom donates or gives up an electron.
6) What is located in the nucleus of an atom?
7) How many Protons does SILICON have? How many electrons in its outer ring?
Protons electrons neutrons
Outer 8
Covalent
ionic
Protons and neutrons

12. Chemical Bonds, Molecules, & Compounds
Bond is union between electrons
Atoms bond to form molecules
Molecules of compounds contain more than one element - H2O

13. Ionic Bonding when you: ION a charged particle
If atom loses
__________ electrons, becomes positively charged ion
_____________ these electrons, becomes negatively charged ion
Charge difference attracts the two ions to each other
Ever hear the phrase “Opposites Attract”……
Not a strong bond
One atom gives and the other recieves
If atom gains

14. Formation of NaCl Na + Cl  NaCl Sodium atom (Na) Chlorine atom (Cl)
Outer shell has one electron
Chlorine atom (Cl)
Outer shell has seven electrons
Na transfers electron to Cl forming Na+ and Cl-
Na + Cl  NaCl

15. Covalent Bonding
Atoms share a pair or pairs of electrons to fill outermost shell wants 8 remember
Sharing is Caring
Strong bonds
Water is held together by a covalent bond
O + O  O2

16. Chemical Bookkeeping
Reactants  Products
Yeilds
OH + H  H2O

17. Try this one>>>>> hahaha
Na + O + H  NaOH

18. Energy and Chemical Reactions
Energy is absorbed or released when chemical bonds are broken and new ones are formed.
For most chemical reactions to begin, activation energy must be added to the reactants
Catalysts /ENZYMES are proteins that reduce the amount of activation energy needed to begin a reaction.

20. Solutions = Solute + Solvent
A mixture in which one or more substances are uniformly distributed in another substance
Made up of:
SOLUTE – substance ___________________ the solution
SOLVENT – substance in which the __________________________________
dissolved in
solute is dissolved in

21. Concentration amount of solute dissolved in a solution (High or Low)
Concentration= mg/mL

22. 0---------------------7-------------------14
The pH Scale H+
Measures ______ concentration of fluid
Highest H Lowest H+
Acidic Neutral Basic
More H3O = More OH-
Hydronium Hydroxide

23. Examples of pH Pure water is neutral with pH of 7.0 Acidic Basic
Stomach acid: pH
Lemon juice: pH 2.3
Basic
Seawater: pH
Baking soda: pH 9.0

24. Buffer Systems Minimize shifts in pH
Partnership between weak acid and base it forms when dissolved
Two work as pair to counter shifts in pH
Jelly fish stings are basic.

25. 3.1 WATER

26. what causes these charges?
Structure of WATER 2 1
___ Hydrogens, ___ Oxygen
(Polar) Covalent Bond
O has a slightly negative (-) charge
H have a slightly positive (+) charge
what causes these charges?

27. Polarity – uneven charge
When the # of protons in two nuclei is NOT the same,
____________ spend more time near nucleus with most protons
Water - electrons more attracted to ____ nucleus than to _____ nuclei
Electrons O H

28. 6P

29. Weak Hydrogen bonds hold Liquid Water together+ + _ H + O H + O _ + H +

30. Hydrogen Bonding - the force of attraction between:
a Hydrogen with a + charge
AND
another atom/molecule with a - charge
- H bonds form, break and reform with great frequency and ease (weak bonds)

31. Hydrogen Bonding holds DNA strands together

32. Atom in one polar covalent molecule can be attracted to oppositely charged atom in another such molecule
UNIVERSAL SOLVENT

33. Spheres of Hydration
Na+
Cl– – +
Fig. 2.16, p. 29

34. Polarity Temperature-Stabilizing Cohesive Solvent Makes Ions
Properties of Water
Polarity
Temperature-Stabilizing
Cohesive
Solvent
Makes Ions

35. Water Is a Polar Covalent Molecule
Molecule has no net charge
Oxygen end has a slight negative charge
Hydrogen end has a slight positive charge O H H

36. Temperature-Stabilizing Effects
absorb a lot of heat
Liquid water can _____________________ before its temperature rises
Why?
Much of the added energy disrupts hydrogen bonding rather than increasing the movement of molecules

37. Water Is a Good Solvent
Ions and polar molecules dissolve easily in water
When solute dissolves, water molecules cluster around its ions or molecules and keep them separated

38. Hydrophilic & Hydrophobic Substances
Hydrophilic substances
Polar
Hydrogen bond with water
Example: sugar, salt
Hydrophobic substances
Nonpolar
Repelled by water
Example: oil

39. Water Cohesion/Adhesion
Hydrogen bonding holds molecules in liquid water together (cohesion) and also attracts to other surfaces (adhesion)
Creates tension
surface

40. cohesion
water sticks to water

41. water sticks to something else
adhesion
water sticks to something else

42. Explains how water defies gravity and travels upwards in plant stems
Explains how water defies gravity and travels upwards in plant stems! Moving up through narrow tubes against the force of gravity is called _______________
capillarity

43. Why Ice Floats
In ice, hydrogen bonds lock molecules in a ________________________ (spread out solid formation)
Water molecules in lattice are spaced farther apart then those in liquid water
Ice is _____________ dense than water
l a t t i c e
less

45. 1. Describe the structure of a water molecule
2. How does polar differ from nonpolar?
3. what happens when ions are mixed with water?
4. Water sticking to water??? Water sticking to anything else??
5. what is capillarity?
6. Antifreeze is used to cool off a car engine. You can replace antifreeze with water for a short time, why???? What property of water allows use to do this??? (think pasta)