Live Lesson 3/20/25

​Live Lesson 3/20/25

Poll

Will fluorine gain or lose electrons to become stable?

Count the valence electrons.

• gain 1

• lose 7

Poll

Will nitrogen gain or lose electrons to become stable?

• gain 3

• lose 5

Poll

Will potassium gain or lose electrons bot become stable?

• It is stable!

Draw

Carbon is in group 14 of the periodic table. Remember that groups 13 through 18 have a number of valence electrons equal to the second digit of the group number. An atom of carbon has 4 valence electrons.

Place 4 dots to represent the valence electrons.

Draw

Fluorine is in group 17 of the periodic table, so it has 7 valence electrons.

Place the first 4 dots on separate sides of the symbol to represent valence electrons.

Place 3 dots in pairs to represent the remaining 3 valence electrons.

​Screenshot this!

Draw

Which of the following are valid Lewis structures for nitrogen?

​Chemical Formulas

Atoms often form chemical bonds to form compounds. A chemical formula is a set of letters and numbers that represents a compound. A chemical formula tells you:

• the types of elements found in a compound; and

• the number of atoms of each element.

A subscript is a number that tells you how many atoms of that element are in a compound.

​Look at the formula. What does the formula tell you?

​Let's figure this out! Copy the formula on your whiteboard and see if you can find the total number of atoms for each element.

​Cu₃(PO₄)₂

Poll

Which concept do you understand the best?

• valence electrons are the electrons in the outermost energy level of an atom

• the octet rule states that elements want eight electrons in the outermost energy level

• Lewis structures are models that show the valence electrons in an atom

• a chemical formula tells you the number of atoms of each element in a compound