The periodic table
Ion
A Charged atom
Period
A horizontal row of elements in the periodic table
Semiconductors
B Si Ge As Sb Te
Nonmetals
H He C N O F Ne P S Cl Ar Se Br Kr I Xe At Rn
Describe why atoms of bromine, Br, are very reactive. To which family does bromine belong
Halogen group
How did Mendeleev arrange the elements in his periodic table
He arranged elements in rows by increasing atomic mass
Describe how Mendeleev Organized his periodic table
He organized his periodic table by putting the elements in rows in order of increasing mass so that elements with similar properties were in the same column
Identify the following on the periodic table A. The chemical symbol for mercury B. The period and group for gold C. The atomic mass of iron D. The atomic number of neon E. The element represented by Cu
Hg Period 6 Group 11 55.845 u 10 Cu
What happens to an atom that gains or loses electrons
It no longer has an equal number of electrons and protons. Because the charges do not cancel completely, the atom has a net electric charge
Identify which element is more reactive: lithium, Li, or beryllium, Be
Lithium, Li
What are the three main categories of elements
Metals Nonmetals and Semiconductors
Classify the following elements as alkali, alkaline-earth, or transition metals based on their positions in the periodic table: A. Fe B. K C. Sr D. Pt
Potassium is a alkali metal, Strontium is a Alkali- earth metal, Iron and Platinum are Transition metals
Compare the number of valence electrons in an atom of Oxygen with the number of valence electrons in an atom selenium
They have the Exact same number of valence electrons
What does each element family have in common
They have the same number of valence electrons
Group
A vertical column of elements in the periodic table; elements in a group share chemical properties
Metals conduct electricity well, while nonmetals do not. Which element should conduct electricity better: Germanium, aluminum, or Helium
Aluminum
Explain why elements in a group on the periodic table have similar chemical properties
Because Their atoms have the same number of electrons in the highest occupied energy level
Explain why Mendeleev left a space for the unknown (at the time) element germanium in his periodic table
Because he predicted that this element would be gray metal that has a high melting point
What are semiconductors
Elements that are able to conduct heat and electricity under certain conditions
State the property used to organize elements in the modern periodic table
Increasing atomic mass
Metal
Li Be Na Mg K Ca Rb Cs Ba Fr Ra Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Al Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn La Hf Ta W Re Os Ir Pt Au Hg Ti Pb Bi Po Ac Rf Db Sg Bh Hs Mt Ds Rg Uub Uuq Uuh Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
List the three main categories of elements, and give an example of each
Metals example: Copper Lead Non Metals Example: Carbon Sulfur Semiconductors example: tellurium silicon
Describe why chemists might sometimes store reactive chemicals in argon, Ar. To which family does argon belong
Noble gases
What are some of the families of nonmetals
Noble gases and the halogens
Describe why lithium and other Group 1 elements usually form positive ions, while fluorine and other Group 17 elements form negative ions
Removing a valence electron of Lithium makes it become positive but adding a valence electron to fluorine makes it become negative
Are the properties of sodium, Na, more like properties of lithium, Li, or magnesium, Mg
Sodium and Lithium are in the same group, so their properties should be more alike than the properties of Sodium and Magnesium
Periodic law
The law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements
How are elements arranged in the modern periodic table
The modern periodic table organizes elements by atomic number
Why do elements within a group of the periodic table have similar chemical properties
Their atoms have the same number of electrons in the highest occupied energy level
What are the families of metals
They include alkali metals, the alkaline-earth metals, and the transition metals
Explain why some atoms gain or lose electrons to form ions
To form a net electric charge
