Question

1. which of the following is not a transition metal?

(a) mg
b. ti
c. cr
d. hg

1. name two other elements that have similar properties to those of potassium.

ar ne
for each of the following sets, choose the correct element and explain your answer.

1. cl, se, br

a. smallest atom?
b. highest ionization energy

1. p, s, na

a. largest atom?
b. lowest ionization energy

1. n, p, as

a. smallest ionization energy
b. largest atom

1. k atom and k⁺

a. which is the largest?

1. cl atom, cl⁻

a. which is smallest?

summary of trends
periodic table chart
trends in ionic radius

• ions in same group have same charge
• ion size increases down the group
• cations smaller than neutral atom
• anions bigger than neutral atom
• cations smaller than anions
• larger positive charge= smaller cation
• larger negative charge= larger anion

general trends in 1st ionization energy

• more coulombic attraction on electron, the more energy it takes to remove it
• the farther the electron is away from the nucleus, the less energy it takes to remove
• 1st ie decreases down the group
• valence electron is farther from nucleus
• 1st ie generally increases across the period
• coulombic attraction increases

Explanation:

Question 7

Step1: Recall transition metal definition

Transition metals are elements in d - block (groups 3 - 12) of periodic table.

Step2: Analyze each option

• Mg (Magnesium) is in group 2 (s - block), not d - block.
• Ti (Titanium) is in group 4 (d - block), transition metal.
• Cr (Chromium) is in group 6 (d - block), transition metal.
• Hg (Mercury) is in group 12 (d - block), transition metal.

Step1: Recall periodic table trends

Elements with similar properties are in the same group. Potassium (K) is in group 1 (alkali metals).

Step2: Identify group 1 elements

Other group 1 elements: Lithium (Li), Sodium (Na), Rubidium (Rb), Cesium (Cs), Francium (Fr). Choose two, e.g., Na and Li.

Step1: Recall atomic radius trend

Atomic radius decreases across a period (left - to - right) and increases down a group (top - to - bottom).

Step2: Locate elements on periodic table

Cl (Chlorine): period 3, group 17; Se (Selenium): period 4, group 16; Br (Bromine): period 4, group 17.
Cl is in period 3 (higher period number means larger radius generally), and across period 3, Cl is on right. Se is in period 4, group 16; Br in period 4, group 17. Cl has smallest radius as it's in lower period and rightmost among them.

Answer:

a. Mg

Question 8