Periodic Table Trends Explained

The video tutorial introduces trends on the periodic table, focusing on the Alpha principle, which helps determine electron orbitals and energy levels. It explains how to count electrons across periods, differentiates between valence and core electrons, and discusses filling electron orbitals using Hund's rule. The tutorial also highlights exceptions in electron configurations, using chromium as an example.

What is the Alpha principle primarily used for?

• Determining the number of protons in an atom

• Counting across the periodic table to find electron orbitals

• Identifying the atomic mass of elements

• Predicting chemical reactions

Which orbital is filled first according to the Alpha principle?

• f orbital

• s orbital

• d orbital

• p orbital

What is the electronic configuration of neon?

• 1s2 2s2 2p6

• 1s2 2s2 2p5

• 1s2 2s2 3p6

• 1s2 2p6

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What are core electrons?

• Electrons in the outermost shell

• Electrons that are not in the valence band

• Electrons that influence chemical properties

• Electrons in the highest energy level

According to Hund's rule, how should electrons be distributed in orbitals?

• Each orbital should have two electrons before moving to the next

• All electrons should fill the lowest energy orbital first

• Each orbital should have one electron before pairing

• All electrons should pair up in the first orbital

What is a full octet?

• Eight electrons in the d orbital

• Eight neutrons in the nucleus

• Eight protons in the nucleus

• Eight electrons in the outermost shell

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Why are noble gases generally unreactive?

• They have a full s orbital

• They have a full d orbital

• They have a full octet of electrons

• They have no electrons

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What is the electronic configuration of titanium?

• 1s2 2s2 2p6 3s2 3p6 4s2 3d2

• 1s2 2s2 2p6 3s2 3p6 4s2 3d10

• 1s2 2s2 2p6 3s2 3p6 4s2 3d5

• 1s2 2s2 2p6 3s2 3p6 4s2 3d1

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What is the correct electronic configuration for chromium?

• 1s2 2s2 2p6 3s2 3p6 4s2 3d4

• 1s2 2s2 2p6 3s2 3p6 4s1 3d5

• 1s2 2s2 2p6 3s2 3p6 4s2 3d5

• 1s2 2s2 2p6 3s2 3p6 4s1 3d4

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Why is chromium an exception to the Alpha principle?

• It has a full s orbital

• It has a completely half-full set of d orbitals

• It has a full p orbital

• It has a full f orbital

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