Chapter 6 Flashcards
How many elements were identified by 1700?
13 elements
Triads
Three elements with similar properties.
How did Dmitri Mendeleev arrange his periodic table?
Elements were in the order of increasing atomic mass.
Periodic Law
When elements are arranged in order of increasing atomic number there is a periodic repetition of their physical and chemical properties.
What three classes make up the periodic table?
Metals, nonmetals, and metalloids.
Metal
Makeup 80% of elements, good conductors, high luster, solid at room temperature, ductile, and malleable.
Conductor
Heat and electricity can easily pass through.
Ductile
Can be drawn into wires.
Malleable
Can be hammered into thin sheets.
Nonmetals
Opposite of metals, more variety in properties, most are gas at room temperature, mostly brittle.
Metalloids
A blending of metal and nonmetal properties, changes based on conditions. Located along the stair-step line.
How many facts are usually in the element’s box on the periodic table?
Four facts.
Atomic number, symbol, name, and atomic mass.
How can elements be sorted into groups?
Based on their electron configuration.
What plays a key role in determining the properties of elements?
Electrons
Noble Gases
Group 18; 8a
Rarely react, outer layers are completely full of electrons.
Representative Elements
Groups 1,2, 13-17; 1a-7a
Some are metals, nonmetals, and metalloids, highest energy levels are not filled.
Transition Elements
Groups 3-12; b groups
Two types: transition metals and inner transition metals.
Atomic Radius
One half of the distance between the nucleus of two atoms of the same element when atoms are joined.
What is the trend of atomic size?
It increases from top to bottom and decreases from left to right.
Ions
A group of atoms that has an electric charge.
Cation
A positive ion, usually a metal
Anion
A negative ion, usually a nonmetal.
Ionization Energy
The energy required to remove an electron from an atom.
What is the trend of first ionization?
Energy tends to increase from left to right and decrease from top to bottom.
How do cations and anions compare to the atoms from which they form?
Why?
Cations are always smaller than the atom.
Anions are always larger than the atom.
Cations have the same amount of protons but a different number of electrons.
Electronegativity
The ability of an atom to attract electrons.
What is the trend of electronegativity?
The values decrease from top to bottom.
What is the trend of representative elements?
The values increase from left to right.
How many electrons are in the outer layer?
1-1 2-2 13-3 14-4 15-5 16-6 17-7 18-8
What does periodic mean?
Repeating or having a pattern.
Atomic Mass
Protons + Nuetrons
Atomic Number
Number of protons
What is room temperature?
70 degrees F
Periodic Table
An arrangement of elements.
