Groups of the Periodic Table and Noble Gas Envy

Admit Slip Where are the noble gases? How many valence electrons do they have? Do any other elements have that number of valence electrons?

Objectives Students will be able to: Identify the groups of the periodic table and their properties Determine what an element has to do to have a noble gas’s electron configuration.

Agenda Admit Slip Notes Video More Notes! Noble Gas Envy Worksheet Product: Noble Gas Envy Worksheet Homework: Finish Worksheet

Groups of the Periodic Table 11/3/10 The columns or groups of the periodic table contain elements with similar properties. The main groups of the periodic table are alkali metals, alkaline earth metals, halogens and noble gases. Another main section of the periodic table are the transition metals.

Alkali Metals Alkali metals are all of the first column except for Hydrogen. Hydrogen is a nonmetal. The alkali metals are really reactive. They react violently with water. They are so reactive that they are never found alone unless they are isolated from air/water.

Alkaline Earth Metals Alkaline earth metals are all of the second column - Be, Mg, Ca, etc. They also react with water though not as quickly or as violently as the alkali metals.

Halogens Halogens are all in the second-to-last column: F, Cl, Br.. They are also very reactive.

Noble Gases Noble gases are all in the last column: He, Ne, Ar, Kr, Xe, Rn They are non-reactive or inert. They do not react. They always stay by themselves as individual elements, and do not form compounds.

Transition Metals Transition metals are the “middle” elements that did not fit the trends of the original 8 groups. Many well known metals such as copper, silver, and gold are transition metals.

Metals Nonmetals and Metalloids Most of the periodic table is made up of metals. The top right corner and hydrogen (H) are nonmetals. In between, there is a group of hybrid metalloids that separate the metals from the nonmetals.

What does this mean for us? Knowing the different groups of elements is important in general, but we also can learn and predict their behavior based on these groups.

For example Let’s look at this video about alkali metals.

Noble Gas Envy 11 / 3 / 10 Noble gases have 8 valence electrons, a full valence shell. This makes them “happy” and “satisfied” and they don’t want to react with anything else. All the other atoms want to be just like the noble gases. They will either LOSE or GAIN electrons so that they have the same electron configuration as the nearest noble gas. Unit 1 • Investigation V

Metaphor The noble gases each have a full table of 8 people at a party. All the other elements also want to be cool and have a full table. If you are sitting at a table with 7 people, what do you want to happen? If you are sitting at a table alone, what do you want to do?

Example 1 Lithium: How many valence electrons does it have? Draw a sketch of its valence shell. Is it closer to go back to the last noble gas or to go forwards towards the next noble gas? Do you think it is easier to gain 7 extra electrons OR to lose 1 electron?

Example 2 Fluorine How many valence electrons does it have? Draw a sketch of its valence shell. Is it closer to go back to the last noble gas or to go forwards towards the next noble gas? Do you think it is easier to gain 1 extra electron OR to lose 7 electrons?

Left-Hand Side Examples Phosphorus How many valence electrons does it have? Draw a sketch of its valence shell. Is it closer to go back to the last noble gas or to go forwards towards the next noble gas? Do you think it is easier to gain or lose electrons to get to that noble gas? How many will it gain or lose? When done, answer the same questions for: Aluminum

Last Slide! Here are some rules to help us with what we just learned. If an element has 1, 2, or 3 valence electrons, it will LOSE all of them to get to 0. If an element has 5, 6, or 7 valence electrons, it will GAIN enough electrons to get to 8. Each element will lose or gain electrons, based on whether 0 (the last noble gas) or 8 (the next noble gas) is closer. Elements with 4 valence e- can lose or gain 4 electrons.

Classwork Please work on the Noble Gas Envy worksheet now. You do not need to finish it, but you need to show me your Exit Slip before you leave!

Exit Slip How many valence electrons do barium atoms have? What would have to happen for a barium atom to have a noble gas configuration? Explain.