The element bromine, Br, has a larger atomic radius than
A) Cu, O and Ba
B) I, Cu, and Ba
C) F and Kr
D) O, F, and Kr
The correct answer and explanation is:
The correct answer is D) O, F, and Kr.
To understand this, we need to consider trends in the periodic table related to atomic size. Atomic radius refers to the distance from the nucleus to the outermost electron. Several factors influence atomic radius, including atomic number and electron shielding.
- Across a period (left to right): As the atomic number increases, protons are added to the nucleus, which pulls the electrons closer to the nucleus. This results in a decrease in atomic radius. Therefore, elements like oxygen (O) and fluorine (F) have smaller atomic radii than bromine.
- Down a group (top to bottom): Atomic radius increases because additional electron shells are added. Each new shell is further from the nucleus, and the increased number of electron shells results in larger atomic radii. Hence, elements like bromine (Br) will have a larger atomic radius than elements like oxygen (O), fluorine (F), and krypton (Kr), which are positioned above it in the periodic table.
- Comparing elements within the same group: Bromine is in group 17 (halogens), while oxygen is in group 16 and fluorine is in group 17 but positioned above bromine. Bromine’s atomic radius is larger than that of oxygen and fluorine due to being further down the group.
In summary, bromine (Br) has a larger atomic radius than elements in group 16 (like oxygen) and group 18 (like krypton), but smaller than elements like barium (Ba) from group 2 or iodine (I) from group 17, making D) O, F, and Kr the correct choice.