Chemistry Chapter 5
Across a period from left to right, the elements become less metallic and more nonmetallic in their properties.
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Identify the elements below: a. element in group 2, period 5 b. element in group 12, period 4
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alkaline earth metals
All alkaline earth metals have two valence electrons. Metals in Group 2A are harder than metals in Group 1A. The melting point of magnesium is 650°C, which is much higher than the melting point of sodium—98°C.
Know the properties of the metalloids and where they are located on the periodic table.
Can be shiny or dull, Conductivity of heat and electricity better than nonmetals but not as good as metals. Solid at room temperature. Ductile, Malleable
halogens have ___
Despite their physical differences, the halogens have similar chemical properties.
differences in reactivity with alkaline earth metals-
Differences in reactivity among the alkaline earth metals are shown by the ways they react with water.
how are elements within a group similar?
Elements in a group have similar properties because they have the same number of valence electrons.
Except for water, most of the compounds in your body contain
Except for water, most of the compounds in your body contain carbon.
Boron family
Group 3A contains the metalloid boron, the well-known metal aluminum, and three less familiar metals (gallium, indium, and thallium). All these elements have three valence electrons.
carbon family
Group 4A contains a nonmetal (carbon), two metalloids (silicon and germanium), and two metals (tin and lead). Each of these elements has four valence electrons. Notice that the metallic nature of the elements increases from top to bottom within the group. Germanium is a better conductor of electric current than silicon.
nitrogen family
Group 5A contains two nonmetals (nitrogen and phosphorus), two metalloids (arsenic and antimony), and one metal (bismuth). Group 5A includes elements with a wide range of physical properties. Nitrogen is a nonmetal gas, phosphorus is a solid nonmetal, and bismuth is a dense metal. All of the elements in Group 5A have five valence electrons.
oxygen family
Group 6A has three nonmetals (oxygen, sulfur, and selenium), and two metalloids (tellurium and polonium). All the elements in Group 6A have six valence electrons.
How is the periodic table organized?
In the modern periodic table, elements are arranged by increasing atomic number (number of protons).
Know the properties of metals and generally where they are located on the periodic table.
Metals are elements that are good conductors of electric current and heat. Malleable, Ductile, Luster, High Density, Good Conductors of heat and electricity, High melting point, hardness
Hydrogen
Most abundant of all elements in the universe. Hydrogen in a nonmetal but it is placed in group 1A because it has one valence electron. At times it is placed above the halogens but it does not have the same electron affinity as the halogen family. Hydrogen can bond with many other elements.
the most abundent element in earths crust is
Oxygen is the most abundant element in Earth's crust.
valence electrons increase how?
Properties vary across a period because the number of valence electrons increases from left to right.
halogens
The elements in Group 7A are called halogens. Each halogen has seven valence electrons. At room temperature, chlorine is a gas, bromine is a liquid, and iodine is a solid.
noble gases
The elements in Group 8A are called noble gases. Helium has two valence electrons. Each of the other noble gases has eight valence electrons. -The noble gases are colorless and odorless and extremely unreactive.
What are some properties of the A groups in the periodic table?
The reactivity of alkali metals increases from the top of Group 1A to the bottom.Lower densities than other metals One loosely bound valence electron Highly reactive
Identify each family of elements and where they are located on the periodic table.
alcali metals alkaline earth metals boron carbon nitrogen oxygen halogen noble gases (in order from left to right on periodic table) study maps
the most abundant metal in Earth's crust.
alluminum
valence electrons
an electron that is in the highest occupied energy level of an atom.
valence electrons play a key role in
chemical reactions.
Be able to tell how many valence electrons an element will have.
depends on groups in periodic table.. group one- 1valence electron... group 2- 2
Know the properties of the nonmetals and generally where they are located on the periodic table.
elements that are poor conductors of heat and electric current Poor Conductors of heat and electricity, dull, Brittle solids, Most are gases at room temperature, Low density, Low melting point, Not malleable, Not ductile
Know where the transition metals are located on the periodic table and why they are called the transition metals.
elements that form a bridge between elements on the left and right sides of the periodic table starts at 3-12 -It doesn't have all of the characteristics to fall into a nonmetal and or a metal group. They have the ability to give a distinct color. look at colored maps
metalloids
elements with properties that fall between those of metals and nonmetals. For example, metals are good conductors of electric current and nonmetals are poor conductors of electric current.
How many periods (rows) are there on the periodic table? How many groups (columns, families)?
groups-32 periods-7
____is the second most abundant element in Earth's crust.
silicon
periodic law
the pattern of repeating properties displayed by elements in the periodic table
alkali metals
these metals have a single valence electron and are extremely reactive. Because they are so reactive, alkali metals are found in nature only in compounds.