What is the nucleus held together by?
A. the attraction between the quarks in the proton and neutrons
B. the attraction between the electrons inside the nucleus
C. the electromagnetic attraction between two neutrons
D. the electromagnetic attraction between two protons

What’s the scientific notation for the number 6,840,000,000

What is the most stable monatomic ion formed from nitrogen

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