Explain why atomic radius decreases as we move to the right across a period for main-group elements but not for transition elements.

Explain the relationship between an element’s row number in the periodic table and the highest principal quantum number in the element’s electron configuration. How does this relationship differ for main-group elements, transition elements, and inner transition elements?

Which one of the following statements is the best explanation for the increase of ionisation energy of the alkaline earth metals when going up in a group? *   a) The force of attraction on valence electrons decreases.   b) The value of n decreases.   c) The value of the effective nuclear charge increases.   d) The value of the atomic radius decreases.   e) All of these statements are good explanations for the observed trend.

4. What does presenter say about the relationship between the number of valence electrons of the main-group element and the group number of that element (except helium)?

Describe the periodic trends for Atomic Radius and Ionization Energy. Define them and describe the trends as you move from left to right in a period and top to bottom in a group on the periodic table.

Which of the following answers is true to describe the general trend for Ionization Energy for the Periodic Table? Group of answer choices   Decreases from top to bottom within a group, Decreases from left to right across a period (row)   Decreases from top to bottom within a group, Increases from left to right across a period (row)   Increases from top to bottom within a group, Decreases from left to right across a period (row)   Increases from top to bottom within a group, Increases from left to right across a period (row)

15. (a) b) Identify the element that is described by the following information. Refer to a periodic table if necessary. It is a group 14 (III A) metalloid in the 3rd period. It is a group 15 (VA) metalloid in the 5th period. It is the other metalloid in group 15 (VA). d) It is a halogen that exists in the liquid state at room temperature. 16. What is the relationship between electron arrangement and the organization of elements in the periodic table?

2. The ionization energy of an element is defined as the amount of energy required to remove an electron from an individual atom. The following table gives the ionization energy (in units of kilojoules per mole) for five metals, listed in alphabetical order. Locate each of these metals on the periodic table and arrange them in order of rows and columns as in the periodic table. (a) Describe the periodic trend in the ionization energy of elements within a group. (b) Describe the periodic trend in the ionization energy of elements across a period. Metal Calcium Magnesium Potassium Sodium Strontium Ionization Energy 590 738 419 496 549 Materials

Explain each of the following observations using principles of atomic structure.  a) Potassium has a lower first-ionization energy than lithium.  b) The ionic radius of N3- is larger than that of O2-.  c) A calcium atom is larger than a zinc atom.  d) Boron has a lower first-ionization energy than beryllium. e) Iodine is a solid at room temperature, bromine is a liquid and chlorine and fluorine are gases.

Consider Si, S, and P.1) Based purely on ideas of electron screening and effective nuclear charge, which of these elements do you expect to have the highest first ionization energy?2) Based on experimental data, P has the highest first ionization energy. Explain this observation in terms of electron configuration arguments.