Predicting chemical reactions…

Atoms react to get the right amount of valence electrons Sodium loses one electron to chlorine Na loses one Cl gains one Afterward they both have 8 ve- They stick together because of their opposite charges Formula: NaCl

Transferring Multiple Electrons More than one electron can be transferred Mg has 2 ve- O has 6 ve- Mg transfers both electrons so that both have 8 ve- Formula: MgO

Transferring multiple electrons Both electrons do not have to be transferred to the same atom Mg has 2 ve- Cl has 7 ve- Mg transfers 1 each to 2 different Cl atoms Formula: MgCl2 “2” subscript shows 2 atoms of Cl are present

Try it! Predict the product these two atoms will make: Which atom will lose? Which atom will gain? How many of each atom are needed to have full valence shells? Write the formula.

Try it! Answer Lithium loses 1 electron Oxygen gains 2 electrons 2 lithium atoms are needed for every 1 oxygen atom Formula: Li2O

Practice For each of these practice problems, give the formula of the compound they will make, and say how many electrons total are transferred. K (1 ve) + F (7 ve) = _____________, ________ electrons are transferred Be (2 ve) + Cl (7 ve) = _____________, ________ electrons are transferred Li (1 ve) + N (5 ve) = _____________, ________ electrons are transferred Al (3 ve) + P (5 ve) = _____________, ________ electrons are transferred

Practice Answers For each of these practice problems, give the formula of the compound they will make, and say how many electrons total are transferred. K (1 ve) + F (7 ve) = KF, 1 electrons are transferred Be (2 ve) + Cl (7 ve) = BeCl2, 2 electrons are transferred Li (1 ve) + N (5 ve) = Li3N, 3 electrons are transferred Al (3 ve) + P (5 ve) = AlP, 3 electrons are transferred

Practice Part 2 For each of these practice problems, give the formula of the compound they will make, and say how many electrons total are transferred. Ca (2 ve) + S (6 ve) = _____________, ________ electrons are transferred Zn (1 ve) + N (3 ve) = _____________, ________ electrons are transferred Al (3 ve) + Br (7 ve) = _____________, ________ electrons are transferred Al (3 ve) + O (6 ve) = _____________, ________ electrons are transferred

Practice Part 2 Answers For each of these practice problems, give the formula of the compound they will make, and say how many electrons total are transferred. Ca (2 ve) + S (6 ve) = CaS, 2 electrons are transferred Zn (1 ve) + N (3 ve) = Zn3N, 3 electrons are transferred Al (3 ve) + Br (7 ve) = AlBr3, 3 electrons are transferred Al (3 ve) + O (6 ve) = Al2O3, 6 electrons are transferred