quiz #1 (chemestry) Flashcards
Metals in the Same Family/Group
Ex: Lithium (Li) and Potassium (K)
Both elements have the same number of valence electrons.
○ Lithium’s valence shell electron (VSE) is closer to the nucleus
than Potassium’s.
○ Potassium’s VSE is more easily lost, so potassium is more
reactive than lithium.
○ Generally, the reactivity increases as you move down a group of metals.
Metals in the same period
Ex. Potassium (K) and Calcium (Ca)
○ Both elements have the same number of shells.
○ Potassium has 1 VSE, while calcium has 2 VSE.
○ Potassium’s 1 VSE is more easily lost, than calcium’s 2 VSE, so
potassium is more reactive than calcium.
○ Generally, as you move across a group of metals from left to
right, the reactivity decreases.
Non-metals in the Same Family/Group
Ex.: Fluorine (F) and Iodine (I)
○ Both elements have the same number of valence electrons and
will gain 1 VSE.
○ Fluorine’s valence shell is closer to the nucleus than iodine’s.
○ Fluorine can more easily gain 1 VSE than iodine, so fluorine is
more reactive than iodine.
○ Generally, as you move up a group of non-metals, the reactivity
increases.
Why do Elements React?
Elements react so that the atoms can have a full
valence shell.
○ Non-metals will “gain” electrons to fill their valence shell.
○ Metals will lose electrons to make their valence shell empty (the closest inner shell which is full becomes the new valence shell).
○ A full valence shell makes the atom/ion most stable and it is referred to as a stable octet.
What are Ions?
●An ion is an atom that has an unequal number of protons and electrons, giving it an overall charge.
●A positively charged ion (cation) is formed when a metal atom loses its valence shell electrons.
●A negatively charged ion (anion) is formed when a non-metal atom gains electrons to fill its valence shell.
Determining Ion Charges
Since an ion has an uneven number of positive and negative charges, this must be shown.
●Metal ions have a positive charge and the value is the same as the number of electrons lost from the valence shell.
●Ex.: Na+1
The sodium atom loses its 1 VSE to become an ion and have
a filled shell
● Now, it has 11 protons and only 10 electrons
● Therefore it has a charge of +1
Determining Ion charges
Non-metal ions have a negative charge and the
value is the same as the number of electrons gained to complete the valence shell.
Eg. O-2
● The oxygen atom gains 2 VSE to become an ion and have a
filled valence shell
● Now it has 8 protons and 10 electrons
● Therefore it has a charge of -2 charge
Drawing Lewis Dot Diagrams of Ions (positive)
For positively charged ions (metal ions):
● Write the chemical symbol
● Draw square brackets around the symbol
● Write the ionic charge in the top right corner outside of the
brackets
● DO NOT draw any valence electrons since they have all been
lost
Drawing Lewis Dot Diagrams of Ions (negitive)
● For negatively charged ions (non-metal ions):
● Write the chemical symbol
● Place the 8 VSE around the symbols in pairs
● Draw square brackets around the symbol and electrons
● Write the ionic charge in the top right corner outside of the
brackets
Physical properties of metals
- Good heat conductor
- shiny appearance
- high density
- good conductors of electricity
-ductile and malleable
-High melting and boiling point
-strong and tough
non-metals physical properties
Has no lustre
not hard (except diamond)
non malleable
non ductable
bad conductor of heat and electricity
solid, liquid, and gas
low density
metalloids physical properties
solids
can be shiny or dull
may conduct electricity
poor conductors of hear
brittle
non ductile
protons
charge: +
symbol: p+
location: nucleus
neutrons
charge: 0
symbol: no
location: nucleus
electrons
charge: -
symbol: e-
location: shells/orbits/energy levels
