Question

identify the period, block, and group in which the elements with the following electron configurations are located. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p¹

○ period3_ blockp_ group5_
○ period4_ blockp_ group3_
○ period1_ blocks_ group4_
○ period7_ blocks_ group3_

Explanation:

Step1: Determine the period

The highest - numbered shell with electrons is the 4th shell (4s and 4p), so the period is 4.

Step2: Determine the block

The last electron enters the p - orbital (4p¹), so the block is p.

Step3: Determine the group

For p - block elements, the group number is calculated as 12+ the number of electrons in the np sub - shell. Here, there is 1 electron in the 4p sub - shell, so the group number is 13 (counting groups in the long - form periodic table), which is equivalent to group 3 in the old 1 - 8A/1 - 8B numbering system for main groups.

Answer:

Period4 Blockp Group3