composition of matter atom= building block of an element smallest part of matter protons= + charge...
TRANSCRIPT
Composition of Matter
Atom= building block of an element
Smallest part of matter
Protons= + charge Neutrons= 0 charge Electrons= -1 charge
Protons & neutrons= IN NUCLEUS
Electrons= Orbit OUTSIDE nucleus
Subatomic Particles
Proton: positive charge, +1 mass, in nucleus
Neutron: no charge, +1 mass, in nucleus
Electron: negative charge, 0 mass, outside nucleus
***# of protons ALWAYS = # Electrons
Identifying Elements: Atomic Number:
number of protons in an element Zr=40 protons…and
_______electrons
Mass Number: Protons + neutrons H= 1 mass # He=4 mass #
1112
Sodium
Atomic number =
Mass Number =
2 - 8 - 1
p+
n
2311
23 protons & neutrons
12 neutrons
In a neutral sodium atom the number of protons (11) = the number of electrons (11)
- 11 protons____________________
4 5
BerylliumAtomic number =
Mass Number =
2 - 2
p+
n
9
4
9 protons & neutrons
5 neutrons
In a neutral beryllium atom the number of protons (4) = the number of electrons (4)
- 4 protons____________________
7 7
Nitrogen
Atomic number =
Mass Number =
2 - 5
p+
n
147
14 protons & neutrons
7 neutrons
In a neutral nitrogen atom the number of protons (7) = the number of electrons (7)
- 7 protons____________________
1616
Sulfur
Atomic number =
Mass Number =
2 - 8 - 6
p+
n
3216
32 protons & neutrons
16 neutrons
In a neutral sulfur atomthe number of protons (16) = the number of electrons (16)
- 16 protons____________________
1414
Silicon
Atomic number =
Mass Number =
2 - 8 - 4
p+
n
2814
28 protons & neutrons
14 neutrons
In a neutral silicon atom the number of protons (14)= the number of electrons (14)
- 14 protons____________________
1920
PotassiumAtomic number =
Mass Number =
2 - 8 - 8- 1
p+
n
3919
39 protons & neutrons
20 neutrons
In a neutral potassium atom the number of protons (19) = the number of electrons (19)
- 19 protons____________________
Periodic Table
Columns on the table are called Groups Group # is # of valence electrons
Rows are called Periods Period # tells how many shells you
have
Atomic Weight & Isotopes
Isotopes= same # of protons & electrons, but DIFFER in neutrons Ex) Hydrogen, H2, H3 They still have same chemical properties
Radioisotopes= heavier isotopes that are unstable and decay Can be harmful to cells Can be used to tag biological molecules
Chemical Compounds
Chemical combination of 2 or more elements
Water = H2O A compound can behave
differently than the elements that make it up Ex) Water. Hydrogen is gas, Oxygen is
gas. Together they form a liquid.
Types of Chemical Bonds: Ionic Bond: when
electrons are transferred from one element to another
When an atom gains electrons, it becomes negatively charged and is called Anion.
Cation = positive charge, when element gave up electron
Covalent Bonds: When atoms
share electrons The valence shell
is satisfied by both molecules
Van der Waals Forces
When atoms share electrons, sharing is not always equal.
+ and – charges attract to each other
Water Polarity
Because of unequal distribution of electrons, water is polar.
Negative pole of oxygen is attracted to the positive pole of hydrogen
Solutions & Suspensions
Solutions=all components in a mixture are equally distributed
Suspensions= mixture of water and undissolved solutes
Solute=substance dissolved Solvent=dissolves solute
Acids and Bases
Acids=produces H ions Value below 7
Bases=produce OH ions Value above 7
Look on pg. 43
pH Scale
Created to indicate the concentration of H ions.
Low # = acid High #= base
Carbon Compounds
Organic Chemistry is the study of all compounds containing carbon
Carbon can form millions of different bonds
4 types of compounds: Carbs Nucleic acids Lipids Proteins
Carbs= main source of energy Proteins= form bones, muscles,
made of amino acids Nucleic Acids= store/transmit
genetic information Lipids= store energy, make up
membranes