Chemical Bonding Leyda 2012

A substance formed when 2 or more elements combine chemically. 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.

The outermost electrons of an atom. 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 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.

2 7 First Orbital: __ Electrons Second Orbital: __ Electrons Third Orbital: __ Electrons 7

family 6. Elements in the same _________ have the same number of valence electrons 7. Atoms of elements in the __________ family have filled outermost electron orbitals and therefore do not form chemical bonds with other atoms. noble gas

Chemical Bonding gain lose full outer orbital ions 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_________. gain lose full outer orbital ions Chemical Bonding

Chemical Bonding positive negative lose gain 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. positive negative lose gain Chemical Bonding

Chemical Bonding 1 losing +1 -1 +2 +1 -2 +/- 4 +3 -3 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__ 1 losing +1 -1 +2 +1 -2 +/- 4 +3 -3 Chemical Bonding

Types of Bonds ionic bond protons electrons neutrons 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 _________ ionic bond protons electrons neutrons Types of Bonds

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

17. Calcium and chlorine may combine to form an ionic compound 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___ ) 2 Cl-1 Ca2+ 2 1 Types of Bonds

covalent bond outermost positively negatively 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. covalent bond outermost positively negatively

19. What is a diatomic element 19. What is a diatomic element? Which elements are often found in nature as diatomic? Elements that always exist in nature as two atoms of the same element covalently bonded. O2, H2, Cl2, N2, F2, I2 Types of bonds

Types of Bonds molecule chemical formula subscript 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_________________________________ ______________________. molecule chemical formula subscript how many atoms of that element are in each molecule Types of Bonds

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?) _________ CCl4 CO2 Types of Bonds

Sodium Extra Practice

Phosphorus Extra Practice

Beryllium Extra Practice

M&M Activity 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