When elements are arranged in order of increasing atomic number
Periodic Law
Good conductors of heat and electric current
Metals
Poor conductors of heat and electric current
Nonmetals
Has properties similar to those of metals and nonmetals
Metalloid
They used properties to organize them into groups
How did chemists begin the process of organizing elements?
He arranged the elements in order of increasing atomic mass
What properties did Mendeleev use to organize the periodic table?
In order of increasing atomic number
How are elements arranged in the periodic table?
Metals, Nonmetals, metalloids
What are three broad classes of elements?
Group 1A elements
Alkali Metals
Group 2A elements
Alkaline earth metals
Nonmetals of group 7A
Halogens
Elements in group 8A
Noble gases
Groups 1A-7A; elements that display a wide range of physical and chemical properties
Representative elements
Group B elements mainly in the main body of the periodic table where their highest occupied s sub level and a nearby d sublevel contain electrons
Transition Metal
The highest occupied s sublevel and a nearby f sublevel generally contain electrons
Inner transition metal
One half of the distance between the nuclei of two atoms of the same element when the atoms are joined
Atomic Radius
An atom or group of atoms that has a positive or negative charge
Ions
An ion with a positive charge
Cation
Ion with a negative charge
Anion
Energy required to move an electron from an atom
Ionization Energy
The ability of an atom of an element to attract electrons when the atom is in a compound
Electronegativity
The close match between the predicted properties and the actual properties of gallium helped gain wider acceptance for Mendeleev’s periodic table
What effect did the discovery of gallium have on the acceptance of Mendeleevs table?
Yes; both carbon and silicon are in group 4A and each has four electrons in its highest occupied energy level
Based on their locations in the periodic table, would you expect carbon and silicon to have similar properties? Explain
Metalloids have Properties that are similar to both metals and nonmetals. How a Metalloid behaves depends on conditions.
In general, how are metalloids different from metals and nonmetals?
Na, Mg, Cl
Which of the following symbols are representative elements: Na, Cl, Fe, Ni, Mg
Aluminum
Which of these metals isn’t a transition metal? Aluminum, silver, iron, zirconium
The first ionization energy is the energy needed to remove a first electron from an atom. The second ionization energy is the energy needed to remove a second electron
Explain the difference between the first and second ionization energy of an element.
The ionic radius of a cation is smaller than the atomic radius of the metal atom
How does the ionic radius of a typical metal compare with its atomic radius?
Nitrogen and phosphorus are in the same group(5A)
In which pair of elements are the chemical properties of elements most similar; explain.
1. Sodium and Chlorine
2. Nitrogen and Phosphorus
3. Boron and Oxygen
1. Sodium and Chlorine
2. Nitrogen and Phosphorus
3. Boron and Oxygen
Nonmetals; the trend is for ionization energy to increase from left to right across a period
Would you expect metals or nonmetals in the same period to have higher ionization energies? Give a reason for your answer.
