Chapter 2:Propeties Of Materials, 2.3:Why Elements React To Form Compounds

What is a compound?

A substance made when two or more different elements chemically combine

Why do elements react?

To become more stable by getting a full outer electron shell

What can atoms do to get a full outer shell?

Gain

What happens when a Group 1 atom reacts?

It loses one outer-shell electron

What ion does a Group 1 atom form?

A positive ion with a +1 charge

What happens when a Group 7 atom reacts?

It gains one electron

What ion does a Group 7 atom form?

A negative ion with a −1 charge

What happens when sodium reacts with chlorine?

Sodium transfers one electron to chlorine

What happens to sodium when it loses an electron?

It becomes a Na⁺ ion

What happens to chlorine when it gains an electron?

It becomes a Cl⁻ ion

What is an ion?

A charged particle formed when an atom gains or loses electrons

What happens when an atom loses electrons?

It becomes a positive ion

What happens when an atom gains electrons?

It becomes a negative ion

What is an ionic bond?

The strong electrostatic attraction between oppositely charged ions

How is an ionic bond formed?

Electrons are transferred between atoms

Why do sodium and chlorine form an ionic bond?

Sodium forms Na⁺ and chlorine forms Cl⁻

What compound forms when sodium reacts with chlorine?

Sodium chloride