Identifying Elements and Electron Configurations

The video tutorial explains how to determine which element is represented by a given electron configuration, specifically one ending in 3d1 4s2. It outlines two main methods: counting the total number of electrons to match the atomic number on the periodic table, and using the periodic table's element blocks to identify the element. The tutorial also covers writing electron configurations in both long and condensed forms, using noble gases for simplification. The example used throughout is scandium, which has 21 electrons.

What is the first step in identifying an element using its electron configuration?

• Count the number of protons

• Identify the element's group

• Count the number of electrons

• Find the element's atomic mass

Which element is represented by the electron configuration ending in 3d1 4s2?

• Scandium

• Titanium

• Chromium

• Vanadium

How do atomic numbers help in identifying elements?

• They indicate the number of neutrons

• They represent the element's group

• They show the element's mass

• They equal the number of electrons in a neutral atom

What is the atomic number of scandium?

• 21

• 20

• 19

• 22

What is the purpose of using a noble gas in electron configuration?

• To increase the number of electrons

• To simplify the notation

• To identify the element's period

• To change the element's properties

Which noble gas is used in the condensed electron configuration of scandium?

• Xenon

• Argon

• Neon

• Krypton

In electron configuration, why is 4s2 often written before 3d1?

• Because 3d1 is closer to the nucleus

• Because 3d1 is more stable

• Because 4s2 is filled first

• Because 4s2 has more electrons

What is an alternative method to identify elements using electron configurations?

• Using element blocks on the periodic table

• Using atomic mass

• Using the element's density

• Using the element's color

What is the significance of valence electrons in identifying elements?

• They show the element's atomic mass

• They determine the element's color

• They help in identifying the element's block

• They indicate the element's density

Which block does scandium belong to in the periodic table?

• p-block

• d-block

• s-block

• f-block