Why is a filled valence shell often called an octet?
With the exception of He, which has 2 valence electrons, the closed shell/noble gas configuration has eight electrons in its valence shell.
Which atom has a partial negative charge in a B-H bond?
Because H is more electronegative than B, H has a partial negative charge.
Which bond should be longer, F-F or Cl-Cl?
Because Cl is in period 3 and F is in period 2, the Cl atom is larger than the F atom. This means that the Cl-Cl bond should be larger.
Which bond should be stronger, H-F or H-Cl?
Because F is both smaller and more electronegative than Cl, it should have a shorter and stronger bond with H than has Cl.