Trends
What is a group?
What is a period?
A group is column.
A period is a row.
Where are metals located relative to the metalloid staircase?
Where are nonmetals located relative to the metalloid staircase?
Metals are to the left of the metalloid staircase.
Nonmetals are to the right of the metalloid staircase.
What does reactivity of metals mean?
Reactivity means how quick the metal is react or change when it comes into contact with another metal.
What is the trend for electronegativity moving across and down?
Electronegativity will decrease moving down a group and increase moving across a period.
Most of the elements on the periodic table are classified as:
metals
What is the trend for reactivity moving across a periodic table?
What is the trend for reactivity moving down a group?
Metals become more reactive moving down a group, but are less reactive moving across a period.
Which two qualities have the same trends moving down and across?
Which trend is different from the others?
Electronegativity and ionization energy will increase moving across a period and they will decrease moving down a group.
Atomic radius is the complete opposite, it will increase moving down a group and decrease moving across a period.
Elements (aside from those with 8 valence electrons) tend to lose/gain _____ electrons to achieve an _____.
valence
octet
Reactivity can be attributed to a metal's _______.
A high value indicates that the metal is _______.
A low value would indicate that the metal is _______.
electronegativity
less reactive
more reactive
Identify the following element with the greatest and the element with the least ionization energy :
N, O, P, and S
P would be the least
If a substance is found to malleable, was not able to conduct electricity, and appears shiny, you would classify it as a:
metalloid (shares properties of metals and nonmetals)
Rank the elements in terms of reactivity from least reactive to most reactive:
Be, Ra, and Ca
Ra, Ca, and then Be
Explain why electronegativity increases moving across (left to right) a periodic table.
OR choose a trend in a direction and justify why it behaves in that direction.
Electronegativity will decrease for the following reasons:
- Atoms moving across having more protons and have the same number of energy levels.
- Since there are more protons, there is a greater force of attraction or pull on the electrons on that given ring.
- The stronger the pull onto the electrons, the stronger the electronegativity -- so it will increase moving across a periodic table.
Explain how we tested for conductivity of metals.
We used an apparatus to test for conductivity. If we set up the apparatus using the alligator clips to connect to the two ends of the LED light and it lights up, electricity passed through. We use an additional alligator clip that we use to touch the substance from the two ends (without the clips touching one another). If the LED lights up, the metal is conductive but if it does not, it is not conductive.
Using your knowledge of ionization energy, electronegativity, atomic structure of atoms, and general periodic trends, explain the trend for reactivity of metals moving across a periodic table and going down the periodic table.
Reactivity of metals is attributed PRIMARILY to its electronegativity.
Electronegativity is how strong the grip is between an atom nucleus (where the protons are) and electrons. Atom are larger (more electrons, more energy levels occupied) as you move down a periodic table and since the distance between the valence electrons and nucleus increases, the grip on the electrons becomes weaker and it is easier for the metal to give up an electron.
Atom are smaller (more protons, same number of energy levels occupied) as you across down a periodic table and since the distance between the valence electrons and nucleus decreases, the grip on the electrons becomes stronger and it takes more energy for the metal to give up an electron.