when 0.5 g mixture of K2CO3/KHCO3 treated with excess HBr solution, the mass of KBr residue left is 0.75 g . what is the percent composition by mass of K2CO3

Omg imgonnafailnfiedkla use complete sentences to explain how the mass of hydrogen is conserved during cellular respiration.

What are the three major branches of natural science? • earth and space science, life science, physical science •earth and space science, physical science, chemistry •physical science, life science, chemistry •life science, chemistry, physics

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