a. 120
B. 60
C. 180
D. 109
E. 90
please explain
2007-02-27 08:33:16 · 3 answers · asked by galdon885 1 in Science & Mathematics ➔ Chemistry
The extra repulsive effect of the lone pairs gets less down the group, and so the bond angle reverts to as near as possible the pure tetrahedral angle, which is almost exactly 109.5.
In water it is 5 degrees less.
2007-02-27 08:58:46 · answer #1 · answered by Gervald F 7 · 0⤊ 2⤋
First draw a Lewis structure then count the number of bonding and nonbonding electrons around the central atom (Selenium in this case). If there are 2 things around the atom (other atoms or lone pairs of electrons) then then the parent geometry will be linear, if there are three it will be trigonal planar, 4-tetrahedral, 5-trigonal bipyrimidal, etc. Then figure out where the lone pairs and other atoms will go. This should tell you what the bond angle is.
Hint: Selenium is under Oxygen, so you will probably get a molecule that looks like H2O.
2007-02-27 08:57:20 · answer #2 · answered by anon 4 · 0⤊ 0⤋
Selenium is in the same column (group) as oxygen and will therefore have similiar bond angles as water. Therefore the answer is D.
2007-02-27 08:54:29 · answer #3 · answered by metalman31 2 · 0⤊ 1⤋