Chapter 5.2. Most often there are 4 pieces of information for each element listed on the periodic...
-
Upload
shonda-neal -
Category
Documents
-
view
216 -
download
1
Transcript of Chapter 5.2. Most often there are 4 pieces of information for each element listed on the periodic...
The Modern Periodic Table
Chapter 5.2
Most often there are 4 pieces of information
for each element listed on the periodic table.
Element Information in the Periodic Table
Most often there are 4 pieces of information
for each element listed on the periodic table.
Element Information in the Periodic Table
Atomic number(# of protons)
Most often there are 4 pieces of information
for each element listed on the periodic table.
Element Information in the Periodic Table
Atomic number
Element symbol(1st capital, 2nd small)
Most often there are 4 pieces of information
for each element listed on the periodic table.
Element Information in the Periodic Table
Atomic number
Element symbol
Element name
Most often there are 4 pieces of information
for each element listed on the periodic table.
Element Information in the Periodic Table
Atomic number
Element symbol
Element name
Atomic mass
Atomic mass depends on:
Distribution of an element’s isotopes Masses of those isotopes.
Isotopes = same element, different masses Masses different because:
Same # protons Different # neutrons
Atomic Mass
Atomic Mass Units
Scientists chose one isotope to serve as a standard.
This isotope is the most abundant one found in nature Carbon-12 atom: 6 protons and 6 neutrons.
1 Atomic Mass Unit (amu) = one twelfth the mass of a carbon-
12 atom.
Atomic Mass
Most elements are mixtures of 2 or
more isotopes. Atomic mass is weighted average.
Example: Chlorine atomic mass = 35.453 amu. Two natural isotopes of chlorine: chlorine-
35; chlorine-37 Chlorine-35: 17 protons and 18 neutrons. Chlorine-37: 17 protons and 20 neutrons.
Elements in modern periodic table arranged
by increasing atomic number (not mass) (Atomic number = # of protons).
Periodic Law - Pattern of Repeating Properties Periods - Each row is a period.
Each period is for a different electron shell or energy level
The Periodic Law
All of the Electron Shells
Modern periodic table – stretched out (7 rows) Shows periods with Lanthanide & Actinide
series where they really belong
The Periodic Law
Elements are also arranged into vertical columns
called Groups (or Families). Sounds of musical notes separated by an octave are related, but they are not identical. Properties of elements in a Group (column) are
related, but not identical. Groups - Each column is a Group (or Family).
Similar electron configurations Similar chemical properties
The Periodic Law
Example: Group 8A (or 18) - Noble Gasses with Full Shells
Helium - Atomic #2
Neon - Atomic #10
Argon - Atomic #18
The Periodic LawPeriodic Table of the Elements
Largest class of elements on the Periodic Table - Metals. 80% of the elements.
Metals
Malleable and ductile (can change
shape) Malleable = compress without breaking Ductile = stretch without breaking
Good Conductors (thermal & electrical) Luster (means they are shiny!)
Physical Properties of Metals
Groups 3 – 12: Form a bridge between elements on the left and right side of the table
Tough, hard, and strong Less reactive than standard metals Have more properties in common than elements in other groups.
Transition Metals
Share characteristics of both metals & non –
metals. Semi – conductors
Metalloids
Insulators (poor conductivity) Living organisms are mostly non-metals.
(especially C, N, O, H) Most of the compounds in your body contain
carbon
Non-Metals
Across a period from left to right, the elements
become less metallic and more nonmetallic in their properties.
From left to right across Period 3, there are three metals (Na, Mg, and Al), one metalloid (Si), and four nonmetals (P, S, Cl, and Ar).
Variations Across a Period
Sodium reacts violently with water. Magnesium will not react with water unless the
water is hot. Aluminum does not react with water, but it
does react with oxygen. Silicon is generally unreactive. Phosphorus and sulfur do not react with water,
but they do react with oxygen. Chlorine is highly reactive. Argon hardly reacts at all.
Variations Across a Period