C9 Flashcards
How are elements classified by period?
Period (horizontal) -> corresponds to the number energy levels
How are elements classified by group?
Group number -> the charge a metal/nonmetal will gain when it is an ion
Metals -> number of electrons lost to create full shell
Nonmetal -> number of electrons gained to create a full shel
What is valency?
Tells you how many bonds an atom can make with another atom
OR
How many electrons its atom can lose/gain/share to form a compound
Group/valency
1/1
2/2
3/3
4/4
5/3
6/2
7/1
8/0
Describe the the changes in metallic and nonmetallic properties as you go across the periodic table
Metallic character of element -> decrease across a period, increases as you move down a group
Metal -> left
Nonmetal -> right
What are the characteristics of metals and nonmetals?
Number of outer shell electrons
Type of bonding
Conducting ability
Type of oxide
React with acids?
Basic properties
Metal:
1-3 outer shell electrons
Metallic bonding
Good electric conductor
Basic oxides
Many react with acids
Malleable, bent and shaped, high melting+boiling point
Nonmetal:
4-7 outer shell electrons
Covalent bonds
Poor electric conductor
Acidic oxides
Don’t react with acids
Flaking, brittle, low melting and boiling point
What is the electronic configuration?
The arrangement of electrons into shells for an atom
Number of notation -> level
Last number -> number of electrons on outer shell
How does electronic configuration relate to periods and groups?
Period: the number of notation shows that it has X amount of levels -> corresponds to the period its on
Group: final notation shows which groups its in
Use this info to find on periodic table
How does having similar chemical properties relate to the groups on the periodic table?
Same group -> similar chemical properties
When atoms collide and react -> outer electrons interact -> along group they have the same amount of
What are the group 1 metals also called? Why?
Alkali metals (one electron on outer shell)
They form alkaline solutions when reacted with water
What are the physical properties of alkali metals?
Soft and easy to cut (softer and denser as you go down (-Na and K))
Shiny silvery surface (when cut)
Conduct heat and electricity
Low melting points and low density (melting point decrease as you go down)
What are the chemical properties of alkali metals?
React with oxygen and water vapor in the air -> stored in oil
If reacted with water -> vigorous reaction, produced alkaline metal hydroxide solution and hydrogen
More reactive as you go down
Compare the characteristics of lithium, sodium and potassium
Melting
Boiling
Reactivity with water (and what they do)
Melting point: K<Na<Li
Boiling point: K<Na<Li
Reactivity with water: Li<Na<K
Lithium melting point high and heat not produced quickly -> lithium doesn’t melt (in reaction)
Sodium -> melts (low melting point + heat from reaction)
hydrogen causes the ball of sodium to move around surface of water
White trail of sodium hydroxide -> dissolves into water
potassium -> melts into shiny ball dashes around surface
Enough heat to produce lilac colored flame
As you go down group 1…
Reactivity increases
Melting and boiling point decrease
Density increases ( - potassium and sodium)
One electron on outer shell makes them very reactive
Why is Sodium more reactive than Lithium?
As electrons get further from the nucleus, the less attraction/force is acting on them so they can more easily move away
Sodium has more energy levels, so it is more reactive than lithium
Why are alkali metals more prone to losing an electron?
Outermost electrons are easily gain/lost/shared
Since there’s only one electron, its easier to lose it then gain more electrons to complete the energy level
