atom. The first ionisation energies of the first 20 elements in the periodic There are various trends in this graph which can be explained by reference to the. Lab: Trends in the Atomic Radius and Ionization Energy. Purpose: To investigate and explain periodic trends in atomic radius and ionization energy. Procedure: Atomic Number. II. relationship observed between other elements? Explain. Period: ______ Date: ______ Finding Patterns in Atomic Radius & Ionization Energy For your graph of Ionization Energy versus Atomic Number, the maximum the relationship between the trends for atomic radius and for ionization energy.
The term period is inclusive of all elements between the ns1 position and the np6 position regardless of sublevel. A group in chemistry is a column of the periodic table.
Periodic groups are sometimes also referred to as families. Some groups also have family names and are sometimes referred to thereby although only the names of groups 1, 2, 16, 17, and 18 are considered valid by IUPAC. Periodic trends are patterns of chemical behavior that can be depended upon to repeat as one moves through the elements in order by atomic number. Plot a point for each of the elements in table one to create a graph of Atomic Radius versus Atomic Number graph 1.
Graphing Exercise * Ionization Energy & Atomic Radius
Use the grid provided on the last page. Write a sentence giving a general description of graph 1.
Use group numbers from the periodic table to make generalizations. Plot a point for each of the elements in table one to create a graph of Ionization Energy versus Atomic Number graph 2. Write a sentence giving a general description of graph 2. On Table 1, use a highlighter or colored pencil to highlight all the data associated with group 1 elements. Compare Table 1 to Graph 1.
- Graphing Exercise * Ionization Energy & Atomic Radius
- Periodic Trends
State the group trend that can be identified for Atomic Radius based on the conclusion above. Choose two colored pencils for highlighting. On your graph of Atomic Radius versus Atomic Number mark the minimums of the 1st-3rd periods using one color and the maximums of those periods using the other color. Make a legend to identify your choices. Moving from left to right across a period, atoms become smaller as the forces of attraction become stronger.
This causes the electron to move closer to the nucleus, thus increasing the electron affinity from left to right across a period. Note Electron affinity increases from left to right within a period.
This is caused by the decrease in atomic radius. Electron affinity decreases from top to bottom within a group. This is caused by the increase in atomic radius. Atomic Radius Trends The atomic radius is one-half the distance between the nuclei of two atoms just like a radius is half the diameter of a circle.
However, this idea is complicated by the fact that not all atoms are normally bound together in the same way. Some are bound by covalent bonds in molecules, some are attracted to each other in ionic crystals, and others are held in metallic crystals. Nevertheless, it is possible for a vast majority of elements to form covalent molecules in which two like atoms are held together by a single covalent bond. This distance is measured in picometers.
Atomic radius patterns are observed throughout the periodic table. Atomic size gradually decreases from left to right across a period of elements.
This is because, within a period or family of elements, all electrons are added to the same shell. However, at the same time, protons are being added to the nucleus, making it more positively charged.
The effect of increasing proton number is greater than that of the increasing electron number; therefore, there is a greater nuclear attraction.
This means that the nucleus attracts the electrons more strongly, pulling the atom's shell closer to the nucleus. The valence electrons are held closer towards the nucleus of the atom. As a result, the atomic radius decreases. The valence electrons occupy higher levels due to the increasing quantum number n. Note Atomic radius decreases from left to right within a period.
This is caused by the increase in the number of protons and electrons across a period. Atomic radius increases from top to bottom within a group. This is caused by electron shielding. Melting Point Trends The melting points is the amount of energy required to break a bond s to change the solid phase of a substance to a liquid. Because temperature is directly proportional to energy, a high bond dissociation energy correlates to a high temperature.
Melting points are varied and do not generally form a distinguishable trend across the periodic table. However, certain conclusions can be drawn from the graph below. Metals generally possess a high melting point.
Most non-metals possess low melting points. The non-metal carbon possesses the highest boiling point of all the elements. The semi-metal boron also possesses a high melting point. Chart of Melting Points of Various Elements Metallic Character Trends The metallic character of an element can be defined as how readily an atom can lose an electron.
How does atomic number affect ionization energy?
From right to left across a period, metallic character increases because the attraction between valence electron and the nucleus is weaker, enabling an easier loss of electrons. Metallic character increases as you move down a group because the atomic size is increasing. When the atomic size increases, the outer shells are farther away.
The principal quantum number increases and average electron density moves farther from nucleus. Note Metallic characteristics decrease from left to right across a period.
Metallic characteristics increase down a group. Electron shielding causes the atomic radius to increase thus the outer electrons ionizes more readily than electrons in smaller atoms. Metallic character relates to the ability to lose electrons, and nonmetallic character relates to the ability to gain electrons.