Question

1. where are the most active metals located?
2. where are the most active nonmetals located?
3. as you go from left to right across a period, the atomic size (decreases/increases)? why?
4. as you travel down a group, the atomic radius (decreases/increases)? why?
5. as you go from left to right across a period, the ionization energy (decreases/increases)? why?
6. as you travel down a group, the shielding effect (decreases/increases)? why?
7. where is the highest electronegativity found?
8. where is the lowest electronegativity found?
9. elements within a group have a similar number of ...
10. elements across a period have the same number of ...
11. define electronegativity.
12. define ionization energy.
13. define shielding effect.
14. define atomic radius.
15. which group of elements have no assigned electronegativities? why?

Explanation:

1. The most active metals are located in the lower - left part of the periodic table, specifically Group 1 (alkali metals) and Group 2 (alkaline earth metals) towards the bottom. This is because they have a low ionization energy and readily lose electrons.
2. The most active nonmetals are located in the upper - right part of the periodic table, mainly in Group 17 (halogens). They have a high electronegativity and readily gain electrons.
3. As you go from left to right across a period, the atomic size decreases. This is because the number of protons increases, resulting in a greater nuclear charge that pulls the electrons closer to the nucleus.
4. As you travel down a group, the atomic radius increases. This is due to the addition of new electron shells, which increases the distance between the nucleus and the outermost electrons.
5. As you go from left to right across a period, the ionization energy increases. The increased nuclear charge makes it more difficult to remove an electron.
6. As you travel down a group, the shielding effect increases. More electron shells between the nucleus and the outermost electrons reduce the effective nuclear charge on the outermost electrons.
7. The highest electronegativity is found in fluorine, which is in Group 17 and Period 2. Fluorine has a strong attraction for electrons.
8. The lowest electronegativity is found in the elements in the lower - left part of the periodic table, such as cesium and francium. They have a weak attraction for electrons.
9. Elements within a group have a similar number of valence electrons, which gives them similar chemical properties.
10. Elements across a period have the same number of electron shells.
11. Electronegativity is the ability of an atom in a chemical bond to attract electrons to itself.
12. Ionization energy is the energy required to remove an electron from a gaseous atom or ion.
13. The shielding effect is the reduction of the effective nuclear charge on the outermost electrons due to the presence of inner - shell electrons.
14. Atomic radius is the distance from the nucleus of an atom to its outermost electron shell.
15. The noble gases (Group 18) have no assigned electronegativities because they have a stable electron configuration and do not readily form chemical bonds, so there is no practical way to measure their ability to attract electrons in a bond.

Answer:

1. Lower - left part of the periodic table (Group 1 and 2 towards the bottom).
2. Upper - right part of the periodic table (Group 17).
3. Decreases; due to increased nuclear charge.
4. Increases; due to addition of new electron shells.
5. Increases; due to increased nuclear charge.
6. Increases; due to more electron shells.
7. Fluorine.
8. Elements in the lower - left part of the periodic table (e.g., cesium, francium).
9. Valence electrons.
10. Electron shells.
11. The ability of an atom in a chemical bond to attract electrons to itself.
12. The energy required to remove an electron from a gaseous atom or ion.
13. The reduction of the effective nuclear charge on the outermost electrons due to the presence of inner - shell electrons.
14. The distance from the nucleus of an atom to its outermost electron shell.
15. Noble gases (Group 18); because they have a stable electron configuration and do not readily form chemical bonds.