You start with 500g of a radioactive substance. You end with 62.5g. The half life of this substance is 33 seconds. How much time has passed?

Look at the bean data from days 4–6. use these data to explain how natural selection changed the number of dark red walking beans over time. writing part

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

If two atoms are bonded to a central atom with no lone pairs, how will they be arranged