{Chemical Bonding

Leyda 2012

1. Define compound:

2. Electrons are found outside the nucleus of an atom. They travel in regions of space called

A substance formed when 2 or more elements combine chemically.

orbitals.

3. What are valence electrons?

Why are they important?

The outermost electrons of an atom.

The valence electrons help scientists predict what chemicals will bond with each other.

4. What determines whether or not an atom will form a chemical bond?An atom will form chemical bonds if it needs to gain or lose electrons to have a full outer orbital.

5. A Bohr diagram shows the location of an atom’s electrons. Begin by putting the first two electrons in the first orbital. Then add up to 8 electrons in the second orbital. The first four electrons occupy separate spaces. The next four electrons each pair up with one of the first four. The third orbital can also hold 8 electrons.

First Orbital: __ Electrons Second Orbital: __ Electrons Third Orbital: __ Electrons

27

0

6. Elements in the same _________ have the same number of valence electrons7. Atoms of elements in the __________ family have filled outermost electron orbitals and therefore do not form chemical bonds with other atoms.

family

noble gas

8. In order to become stable, atoms will either _____ or ________ electrons. An atom will bond with another atom if the bonding gives both atoms________________________. 9. Atoms that have gain or lost electrons are called_________.

Chemical Bonding

gain

lose

full outer orbital

ions

10. When atoms lose electrons, the form ions with_________ charge. When atoms gain electrons, they form ions with _________ charge.11. Atoms on the left side of the periodic table tend to ______ electrons. Atoms on the right side of the periodic table tend to______ electrons.

Chemical Bonding

positive negativ

e

losegain

12. Sodium has __ valence electron(s). It tends to form ions by _______ valence electron(s). The charge on sodium ion is ____.13. Predict the charge on ions of the following elements:Cl __ Mg__ Li__ O__ Si__ Al__ N__ Ne__

Chemical Bonding

1losing +1

-1 +2

+1

-2 +/- 4

+3

-3 0

14. A bond that involves a transfer of electrons from one atom to another is called an_________________.15. Atoms of a given element always have the same number of___________, but can have different numbers of_________ or _________

Types of Bonds

ionic bond

protonselectrons neutrons

16. In an ionic bond, one atom ______electrons while the other__________ electrons. Thus, ionic bonds usually form between atoms from opposite sides of_______________.

gainsloses

periodic table

17. Calcium and chlorine may combine to form an ionic compound. Predict how atoms of chlorine would bond with one atom of calcium.____ (Hint: what is the charge on each of the ions involved _____ _____ )

How many electrons does calcium need to gain/lose____ How many electrons does each chlorine atom need to gain/lose___ ) Types of Bonds

Cl-1 Ca2+

2

21

18. A bond that forms when electrons are shared between atoms is called a____________ ___________. The shared electrons are in the _____________ energy level of both atoms at the same time. The _____________ charged nucleus of both atoms attracts the ___________ charged electrons that are being shared.

covalentbondoutermost

positively negatively

19. What is a diatomic element?

Which elements are often found in nature as diatomic?

Types of bonds

Elements that always exist in nature as two atoms of the same element covalently bonded.

O2, H2, Cl2, N2, F2, I2

20. The combination of atoms formed by a covalent bond is called a _______________ and is represented by a ___________ ____________ which contains the symbol of each element involved in the bond. Following each symbol is a ____________, or a small number which indicates_________________________________ ______________________.

Types of Bonds

moleculechemical formula

subscripthow many atoms of that element are in each molecule

21. What is the chemical formula for a molecule that has one carbon atom and four chlorine atoms?__________

What is the chemical formula for carbon dioxide?( Hint: what does di- mean?) _________

Types of Bonds

CCl4

CO2

Sodium

Extra Practice

Phosphorus

Extra Practice

Beryllium

Extra Practice

Do Not Eat YET! Place M&M’s in the correct orbital(s).

Then identify how many valence electrons the element has.

M&M Activity

Nitrogen

Lithium

Magnesium

Chlorine

Sodium

Fluorine

Oxygen

Argon