Question

1. using the periodic table below, create a diagram that displays the five periodic trends discussed in class.

a. use a different color for each trend. an arrow should point in the direction of an increase for that value.
periodic table of the elements

b. are there any trends that show similar patterns? if so, provide an explanation for why these trends are grouped this way. if not, describe why these trends do not have any common patterns.

1. in class, there was a video showing the alkali earth metals added to water. the elements used in the demonstration with mr. becker included the following three elements:

i. sodium (na) ii. potassium (k) iii. lithium (li)
a. which of the trends would be used to explain what was observed in class?
b. arrange the three elements above in order of decreasing values (highest to lowest)

Explanation:

Step1: Identify the periodic trends

The main periodic trends are atomic radius (increases down a group and decreases across a period), ionization energy (decreases down a group and increases across a period), electron - affinity (varies with some general trends), electronegativity (decreases down a group and increases across a period) and metallic character (increases down a group and decreases across a period).

Step2: Answer 1a

To create the diagram, for atomic radius, an arrow pointing down a group and to the left across a period (colored orange for example) shows increase. For ionization energy, an arrow pointing up a group and to the right across a period (colored blue) shows increase. For electron - affinity, an arrow pointing generally up a group and to the right across a period (colored green) shows increase. For electronegativity, an arrow pointing up a group and to the right across a period (colored red) shows increase. For metallic character, an arrow pointing down a group and to the left across a period (colored purple) shows increase.

Step3: Answer 1b

Ionization energy, electronegativity and electron - affinity have similar patterns. This is because they are all related to the attraction between the nucleus and the electrons. As the effective nuclear charge increases (across a period), these properties increase. As the number of electron shells increases (down a group), the attraction between the nucleus and the out - most electrons decreases, causing these properties to decrease.

Step4: Answer 2a

The trend of ionization energy can be used to explain the reactivity of alkali metals with water. Lower ionization energy means the metal can more easily lose an electron, making it more reactive with water.

Step5: Answer 2b

The order of decreasing ionization energy (and thus decreasing reactivity with water in this context) for sodium (Na), potassium (K) and lithium (Li) is: Li > Na > K. This is because ionization energy decreases down a group in the periodic table.

Answer:

1a: Diagram should have arrows of different colors for each trend as described.
1b: Ionization energy, electronegativity and electron - affinity have similar patterns due to effective nuclear charge and number of electron shells.
2a: Ionization energy.
2b: Li > Na > K