Question

Use the periodic table to determine the number of 3d electrons in Sc. number of 3d electrons: ?

Use the periodic table to determine the number of 4p electrons in Se. number of 4p electrons: ?

Answer 1

Answer: The scandium Sc has one 3d electron and Se has four electrons in 4p orbital.

Explanation:

The scandium belongs to the d block element, its atomic number is 21, and it contains one 3d electron, and thus number of d electrons is one.

Selenium belongs to the oxygen family which is the 16th group, the element that has four electrons in p orbital belongs to this group. The outer electronic configuration of selenium should be 4p3 in the outer orbital. The number of d electrons is four.

Answer 2

Scandium (Sc) has 1 electron in its 3d subshell, while selenium (Se) has 4 electrons in its 4p subshell, as determined by examining their positions on the periodic table and their electron configurations.

Step-by-step explanation:

Using the periodic table, we can ascertain the electron configuration of elements, which helps us determine the number of electrons in particular subshells. For scandium (Sc), which is the first element in the transition metals, additional electrons begin to fill the 3d subshell. Since Sc has an atomic number of 21, its electron configuration ends in 3d1. Therefore, it has 1 electron in its 3d subshell.

For selenium (Se), it has an atomic number of 34, and its electron configuration up to the 4p subshell is [Ar] 3d10 4s2 4p4. This means that Se has 4 electrons in the 4p subshell.