Electron Configuration of First 20 Elements

The video tutorial explains atomic numbers and atomic mass, highlighting how they indicate the number of protons, neutrons, and electrons in an atom. It introduces electron configurations, detailing how electrons occupy specific shells around the nucleus. The tutorial provides examples using the first 20 elements, emphasizing the relationship between electron configurations, group numbers, and period numbers in the periodic table. Exercises are included to practice drawing electron configurations. The video concludes by summarizing the key points and hinting at more complex topics for future lessons.

What does the atomic number of an element indicate?

• The number of neutrons in the nucleus

• The number of protons in the nucleus

• The total number of protons and neutrons

• The number of electron shells

How many electrons can the second electron shell hold?

• 8 electrons

• 2 electrons

• 4 electrons

• 6 electrons

Which element has its valence electrons in the fourth electron shell?

• Nitrogen

• Calcium

• Oxygen

• Helium

In the periodic table, what does the group number indicate about an element?

• The atomic mass

• The number of valence electrons

• The number of protons

• The number of electron shells

What is the maximum number of electrons that can initially occupy the third electron shell?

• 2 electrons

• 8 electrons

• 10 electrons

• 18 electrons