Atomic Radius vs. Atomic Number

1. Which is the largest of the first 54 elements? – Since atomic radii increases as we go down a group of elements or as we go from right to left across a row. Thus, up to the 54th element, rubidium has the largest atomic radii while, helium would have the smallest.
2. Describe how the atomic radius varies within a period and within a family. – Atomic radii vary in a predictable and explicable manner across the periodic table. Radii generally decrease from left to right along each period (row) of the table, from the alkali metals to the noble gases; radii increase down each group (column).
3. Use your graph to predict the atomic radius of the following elements:                     cesium – 0.280 (b)   tungsten – 0.145      (c)    thallium – 0.175        (d)   radon – 0.135
4. Which group of the main group elements contains the largest elements? – The largest elements are found in group 1 which is the alkali metals since atomic radii is bigger on the left side.

Ionization Energy vs. Atomic Number

1. How would you explain ionization energy to your partner?

a. How does the ionization energy vary within a period and within a family? – Moving left to right within a period or upward within a group, the first ionization energy generally increases. As the atomic radius decreases, it becomes harder to remove an electron that is closer to a more positively charged nucleus.

b. Which element on your graph has the strongest hold of its valence electrons? – Helium

2.   (a) Write the electron configuration for chlorine. – [Ne] 3s2 3p5

(b) Which electron is lost when 1251 kJ/mol of energy are applied to a sample of chlorine atoms? –     Chlorine loses its outermost electron when 1251 kJ/mol of energy are applied to it

3. Compare the ionization energies of metals to nonmetals. – Nonmetals have a lower ionization energy than metals. The ionization energy of nonmetals is usually lower than 0.1, while the ionization energy of metals is usually greater than 0.1.

Melting Point vs. Atomic Number

1. Describe the trend of melting points within a period – Melting points and boiling points show periodic properties. This means that they vary in a regular pattern depending on their position within the periodic table. The graphs above show the melting and boiling points for the period 2 and period 3 elements. A trend can also been seen on descending a group.
2. Which group of elements tends to have the highest melting points – Group 6 tends to have the highest melting points. Group 6 contains Tungsten which has the highest melting point of all elements.
3. Tungsten is used in incandescent light bulbs because it has an extremely high melting point. Which element on your chart could be a reasonable replacement for tungsten? Why? – Carbon could be a reasonable replacement for tungsten because it also has a fairly high melting point at 3550 °C.

Density vs. Atomic Number

1. Describe how density varies within a period. – Generally, the density will increase as you go left to right. However, keep in mind that the density of gaseous elements will be much lower than solids.
2. Compare the densities of the elements in the second period with the elements in the third period. – The densities of the elements in the second period, tend to be lower than the densities of the elements directly below them in the third period.
3. Assume that the transition metals given in the table are representative of the other members of this group. How do the densities of the transition metals compare with those of the elements in the main group? The transition metals tend to have much greater densities than the other elements in the main group. The densities of transition metals are usually in the thousands while, the other elements are usually in the hundreds.
4. Explain why aluminum and magnesium are more suitable than iron for use in some airplane parts.

Aircrafts need to be made of light-weight materials such as aluminum and magnesium. To make an airplane body and its parts, a metal needs to be strong and light in weight. Every bit of weight saved in construction means extra payload can be carried, i.e. more luggage and/or passengers – so the company makes more money. Aluminum and Magnesium are much more suitable than iron, because of their low density compared to iron’s very high density.

Electronegativity vs. Atomic Number

1. Describe how electronegativity varies within a period. – In a period, the electronegativity generally increases as you move from left to right.
2. Describe how electronegativity varies within a family. – In a family, the electronegativity decreases when moving from top to bottom. This is the case with all families except for the Noble Gases.