What are ions? When atoms gain or lose electrons they become ions This means they are no longer neutral Unit 3: Chemistry. Ions and Ionic Bonding

What are ions?

• When atoms gain or lose electrons they become ions

• This means they are no longer neutral

Unit 3: Chemistry. Ions and Ionic Bonding.

Becoming Happy Atoms• Gaining or losing electrons help elements to

become stable (non-reactive)

• A stable element has 8 electrons in its valance shell (exception: Helium - He)


Becoming Stable Atoms – Continued• An atom is likely to lose electrons if it has few

valence electrons in its shellExample: metals

• An atom is likely to gain electrons if it has many electrons in its shell (non-metals)Example: non-metals


How to Write an Ion• When an atom loses an electron it becomes positive• When an atom gains an electron it becomes negative

• E.g 1) Sodium (Na) loses an electron to become _______

2) Fluorine (F) gains an electron to become ________



• Most metals tend to lose electrons• Most nonmetals tend to gain electrons


More about Ions

1. A) Will chlorine gain or lose electrons?B) How many?C) Does it keep the same outermost level?

2. A) Will aluminum gain or lose electrons?B) How many?C) Does it keep the same outermost level?


Examples

• The force of attraction between a positively and negatively charged ion.

• Metals tend to lose electrons in chemical reactions to form positive ions

• Nonmetals tend to gain electrons forming negative ions

• Ionic bonding usually occurs between metals and nonmetals


Ionic Bonding

Ionic Bonding Review• An ion forms when an atom gains or loses an

______________

• Positively and negatively charged ions are attracted by ____________ bonds

• These bonds usually form between metals and ______________.

• Examples: ___________, bases, & __________.

ionic

acids

electron

Non-metals

salts


Electrostatic Attraction


Ionic Bonding Examples

1. Write the symbol of the element

2. Find out how many valence electrons the element has and place them around the atom in pairs of 2

**These models only show VALENCE ELECTRONS.**


Drawing Lewis Dot Models


Lewis Dot Structure for Ionic Bonds


Calcium Chloride

• What happens when an atom gains or loses neutrons?

Isotopes!


Flashback!

• In your journals, please answer the following questions:

1. What is an ion and how do they form.

2. How does ionic bonding occur?


Exit Ticket

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What are ions? When atoms gain or lose electrons they become ions This means they are no longer neutral Unit 3: Chemistry. Ions and Ionic Bonding