Unit 03 - Chemical Bonding - Types of Bonds

Chemical Bonding

​Ions

• ​Ions are atoms that have lost or gained electrons.

​What will they do?

• ​ Metals are elements that will lose electrons and will form cations.

• ​ Nonmetals are elements that will gain electrons and will form anions.

Multiple Select

Which of the following are examples of anions?

• K⁺

• S^-2

• Cl^-

• Mg⁺²

Multiple Select

Which of the following are cations?

• Cr⁺³

• O^-2

• S^-2

• Ba⁺²

Multiple Choice

Potassium (K) is a group 1 element. Elements in this group are _____.

• metals and form anions

• nonmetals and form cations

• metals and form cations

• nonmetals and form anions

Multiple Choice

Iodine (I) is a group 17 element. Elements in this group are _____.

• metals and form anions

• nonmetals and form cations

• metals and form cations

• nonmetals and form anions

​transfer of electrons

Think about it:

• What happens when potassium (K) and iodine (I) atoms form chemical bonds?

​Answer

Potassium

• is a group 1 element with 1 VE

• When potassium bonds with iodine it will lose a valence electron

​

Iodine

• is a group 17 element with 7 VE

• it will gain 1 electron on its outer ring (shell) from potassium.

​

In this case the electrons are TRANSFERRED, not shared.

Ionic Bonds

​These are formed when valence electrons are transferred from one atom to another.

​

• ​ionic bonds are formed between metals and nonmetals

​Superscripts

​The charges that you see written next to ions after they have gained or lost electrons are called superscripts.

• Superscript means "written above."

• ​Superscripts tell us:

  1. ​how many electrons were gained or lost

  2. ​if it is an anion or a cation

Multiple Choice

Magnesium is a group 2 element. When it bonds with a nonmetal in group 16 what will the superscript be and what does it mean?

• ⁺2; meaning it has gained electrons

• ^-2; meaning it has gained electrons

• ⁺2; meaning it has lost electrons

• ^-2; meaning it has lost electrons

​Covalent Bonds

These types of bonds happen when valence electrons are shared between atoms.

• Covalent bonds are formed between 2 or more nonmetals

  • Molecules are the result of atoms sharing electrons to form neutral atoms

Multiple Choice

Covalent bonds are formed between what types of elements?

• metals and nonmetals

• transition elements

• nonmetals

• metals

Multiple Select

Which of the following are examples of covalent bonds?

• LiF

• NH₃

• NaBr

• CO