select the correct answer. which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li
select the correct answer. which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li
Answer
Explanation:
Step1: Recall atomic - size trends
Atomic size increases down a group and decreases across a period. Cations are smaller than their parent atoms.
Step2: Analyze the position of elements
K (potassium) is in Group 1, Period 4. Ca (calcium) is in Group 2, Period 4. Li (lithium) is in Group 1, Period 2. $K^+$ is a cation of K and $Ca^{2 + }$ is a cation of Ca.
Step3: Compare sizes
Since atomic size increases down a group, K and Ca are larger than Li. Among K and Ca, K is larger as it is in Group 1 and Ca is in Group 2 (atomic size decreases across a period). Also, cations ($K^+$ and $Ca^{2+}$) are smaller than their parent atoms.
Answer:
A. K