Question | Answer |
What are valance electrons? | electrons in the outer most energy level that have the highest energy |
Which electrons are responsible for bonding? | valence electrons |
What makes an atom stable? | Having a full outer shell (most need 8 valence electrons) |
What is a chemical bond? | the force of attraction holding atoms together |
What happens when a bond is formed? | 1. electrons can be transferred from one to another.
2. Electrons can be shared between atoms |
What are the most reactive metals and where are they on the periodic table? | Alkali metals in group 1. |
How do alkali metals react? | lose one electron |
How do alkaline earth metals react? | lose 2 electrons |
Where are the most reactive nonmetals and what are they called? | halogens located in group 17 |
How do halogens react? | gain one electron |
What is an ion? | an atom that has gained or lost electrons; an electrically charged atom |
If an atom loses an electron, what is its charge? | positive |
If an atom gains an electron, what is its charge? | negative |
What is a negative ion called? | anion |
What is a positive ion called? | cation |
What is an ionic bond? | bond between two ions of oppositive charge |
What charge does an ionic compound have? | neutral (the positive and negative balance/equal each other out) |
What is the small number written to the right and just below the atomic symbol? | subscript |
When you have an ionic compound, which ion is written first? | the metal, which is the cation, which is the positive ion because it lost electrons (it lost its negative!) |
What does stable mean? | not likely to react |
When are H and He stable? | when they have 2 valence electrons |
When can a new or different substance form? | in chemical reactions when bonds are broken and new bonds are formed |
BE FAMILIAR WITH THE MATERIAL ABOUT THE PERIODIC TABLE | STUDY PAGES 152-156 |
Explain the reactivity of metals on the periodic table | decreases from left to right from top to bottom down each group |
Explain the reactivity of metals in groups 1 and 2 | increases from top to bottom down each group |
What is the most reactive element, which group is it found in? | Fluorine, group 17 |
How do atoms with 5, 6, or 7 valence electrons become more stable? | by gaining electrons |
How do atoms with 1, 2, or 3 valence electrons become more stable? | by losing electrons |
How do atoms with 4 valence electrons become more stable? | sometime gain or sometimes lose, depending on the situation |
What is a chemical formula? | combination of atomic symbols and subscript to show the ratio of atoms in the compound |
What information does the subscript give you? | the ratio of atoms of the elements in the compound |
When naming ionic compounds, what is listed first? | the metal or cation |
When naming ionic compounds, what is listed second and given an "ide" ending? | the nonmetal or anion |
If no subscript is written, what is it understood to be? | one |
When naming compounds with polyatomic ions, which is listed first? | positive polyatomic ion |
When naming compounds with polyatomic ions, which is listed second? | negative polyatomic ion with its ending of -ide or -ate |
Name properties of ionic compounds. | hard, brittle, crystals, high melting points, conduct electricity when melted or dissolved in water |
What is a crystal? | orderly, 3D arrangement of ions in a regular, repeating pattern |
Why are ionic compounds hard and brittle? | every ion is attracted to every other ion of the opposite charge around it so the compound is held very tightly and is very strong |
Why do ionic compounds have high melting points? | because ionic bonds are strong, a lot of energy is needed to break the bond. A lot of energy has to be added, hence the high melting point |
What is electric current? | a flow of charged particles (electrons) |
Why do ionic compounds in solid form not conduct electricity while ionic compounds in liquid form do conduct electricity? | in a solid form, ions are not free to move. If the ions can't move, the charged particles can't flow |
What is the oxidation number? | an atom's ionic charge |
How is the oxidation number determined? | from the number of valence electrons that are gained or lost |
What is the Octet rule? | when bonding, all atoms either gain or lose electrons so they end up with the electron configuration of the nearest noble gas |
What are Lewis Structures? | dot diagrams, a simplified what to show how the valence electrons are arranged in the outer shell when chemical reactions take place |
How can you determine how many dots are in each element? | the number of electrons in the outer shell or look at the group number on the periodic table ( example: group 13, 3 valence electrons |