Question

periodic trends 1 & 2 practice

1. why does fluorine have a higher ionization energy than iodine?
2. why do elements in the same family generally have similar properties?
3. indicate whether the following properties increase or decrease from left to right across the periodic table.

a. atomic radius (excluding noble gases)
b. first ionization energy

1. what trend in atomic radius occurs down a group on the periodic table? what causes this trend?
2. rank the following elements by increasing atomic radius: carbon, aluminum, oxygen, potassium.
3. which atom in each pair that has the largest atomic radius?

a. al or b
b. na or al
c. s or o
d. o or f
e. br or cl
f. mg or ca

1. which atom in each pair that has the greater ionization energy?

a. li or be
b. ca or ba
c. na or k
d. p or ar
e. cl or si

Explanation:

1. Fluorine has a higher ionization energy than iodine because fluorine has a smaller atomic radius and a greater effective nuclear charge, making it harder to remove an electron.
2. Elements in the same family have similar properties because they have the same number of valence electrons, which determines their chemical behavior.
3. a. Atomic radius (excluding noble gases) decreases from left - to - right across the periodic table due to increasing effective nuclear charge. b. First ionization energy increases from left - to - right across the periodic table as the effective nuclear charge increases and the atomic radius decreases, making it harder to remove an electron.
4. Down a group on the periodic table, atomic radius increases. This is caused by the addition of new electron shells, which increases the distance between the nucleus and the outermost electrons.
5. Oxygen < Carbon < Aluminum < Potassium. Oxygen and carbon are in period 2 with oxygen having a greater effective nuclear charge, so oxygen is smaller. Aluminum is in period 3 and potassium is in period 4, so potassium is the largest among them.
6. a. Al; b. Na; c. S; d. O; e. Br; f. Ca. Atomic radius increases down a group and decreases across a period.
7. a. Be; b. Ca; c. Na; d. Ar; e. Cl. Ionization energy generally increases across a period and decreases down a group.

Answer:

1. Fluorine has a smaller atomic radius and greater effective nuclear charge.
2. They have the same number of valence electrons.
3. a. Decreases; b. Increases
4. Increases; addition of new electron shells.
5. Oxygen, Carbon, Aluminum, Potassium
6. a. Al; b. Na; c. S; d. O; e. Br; f. Ca
7. a. Be; b. Ca; c. Na; d. Ar; e. Cl