Essential Elements of Life and Atomic Structure

Question-and-answer flashcards covering essential elements, valence electrons, bonding rules (octet rule), oxidation/reduction, and atomic identity based on the lecture notes.

What four elements make up about 96% of living matter?

Carbon, hydrogen, oxygen, and nitrogen.

What is a characteristic of essential life elements in terms of their atomic numbers?

They have atomic numbers less than 21.

What primarily determines the chemical behavior of an atom?

The valence electrons (outermost electrons).

Where are valence electrons located?

In the outermost shell, the valence shell.

What is the Octet Rule?

Atoms tend to have eight electrons in their valence shell for stability.

What can atoms with incomplete valence shells do in bonding?

They can share or transfer valence electrons with other atoms.

How are ions formed?

From the transfer of electrons from one atom to another.

What is oxidation in redox chemistry?

Loss of an electron.

What is reduction in redox chemistry?

Gain of an electron.

What happens if you change the number of protons in an atom?

You obtain a different element.

What happens if you change the number of neutrons in an atom?

You obtain isotopes of the same element.

What happens if you change the number of electrons in an atom?

You obtain an ion (cation or anion) of the same element; electrons influence chemical behavior.

Which subatomic particle is responsible for the chemical identity of an element?

Protons.

Which subatomic particle primarily influences chemical behavior?

Electrons.